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BP: Synthesis and properties of boron phosphide

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Abstract

Cubic boron phosphide, BP, is notorious for its difficult synthesis, thus preventing it from being a widely used material in spite of having numerous favorable technological properties. In the current work, three different methods of synthesis are developed and compared: from the high temperature reaction of elements, Sn flux assisted synthesis, and a solid state metathesis reaction. Structural and optical properties of the products synthesized from the three methods were thoroughly characterized. Solid state metathesis is shown to be the cleanest and most efficient method in terms of reaction temperature and time. Synthesis by Sn flux resulted in a novel Sn-doped BP compound. Undoped BP samples exhibit an optical bandgap of∼2.2 eV while Sn-doped BP exhibits a significantly smaller bandgap of 1.74 eV. All synthesized samples show high stability in concentrated hydrochloric acid, saturated sodium hydroxide solutions, and fresh aqua regia.

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... Zheng et al. got a new record-high 490 W/(mK) at room temperature [38]. Different from 2D graphene and BN, BP has not only high isotropic thermal conductivity, but also exceptional chemical refractory properties, high thermal stability, and large elastic modulus as well as a unique potential to be used in nuclear and radiation detectors [42][43][44]. The coefficient of thermal expansion (CTE) of BP (3.2 ± 0.2 × 10 − 6 / • C) is compatible with many commercial semiconductors, such as Si, SiC, GaN, and GAs, in comparison in diamond [45]. ...
... Ni powders are the common flux for crystal synthesis, including BP [37,43]. After B powder loading and phosphating process at high temperature, 3D-BP@Ni duplicated the interconnected structure of Ni foam, as schematically shown in Fig. 1(a). ...
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Recently, construction of effective three-dimensional (3D) heat transfer networks inside polymer has emerged as a promising design strategy to improve the isotropic thermal conductivity for electronic packaging materials. Hexagonal boron nitride (BN) sheets are popular carriers for constructing 3D networks. But removing overheat capability of BN was greatly sacrificed due to size limitation when constructing 3D network. Herein, a novel 3D heat-transferring network, interconnected boron phosphide (BP) grains in-situ growing on Ni foam, was designed to alternate 3D BN network. An isotropic [email protected] network with high-quality and integrity was successfully fabricated by a simple high temperature treatment. The synthesized [email protected] was incorporated into epoxy resin (ER) by infiltration to fabricate composites. ER/[email protected] composite, with strong interfacial adhesion between epoxy and [email protected], achieved a high thermal conductivity of 2.01 W/(mK), which corresponded to 908.53% and 402.00% enhancement compared to pure epoxy and ER/Ni composite. The coefficient of thermal expansion (CTE) of the composite reached as low as 26.95 × 10⁻⁶/°C, much smaller than epoxy of 60.69 × 10⁻⁶/°C and ER/Ni composite of 59.42 × 10⁻⁶/°C. The designed ER/[email protected] composite has distinguished heat removal and CTE with semiconductors from traditional polymer composites containing 3D BN network. This strategy is promising to promote the development of electrical packaging materials with high isotropic thermal conductivity.
... BP is notoriously difficult to synthesize due to the simultaneous presence of a highly inert (B) and a volatile species (P). 27 High growth temperatures (typically above 900°C) are necessary to activate boron diffusion and obtain crystalline BP, but at these temperatures BP tends to decompose into boron-rich phosphides (such as B 6 P) and gaseous phosphorus. 3,28 For this reason, previous thin-film work on BP has given strong preference to CVD processes near atmospheric pressure where it is easier to prevent P losses by keeping a high P partial pressure during deposition. ...
... The Raman spectrum of this sample ( Fig. 2(b)) is similar to spectra reported for high-quality BP crystals and singlecrystalline films. 27,38,45 The main peak at 827 cm −1 and the secondary peak at 797 cm −1 can be attributed to the Raman-active longitudinal (LO) and transverse (TO) optical phonon modes at the Γ point, respectively. 15 Our 24 h-long anneals result in phase segregation on the film surface, clearly visible in Fig. 3(b), and in a new XRD peak at 31.0°2θ ( Fig. 2(a)). ...
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With an indirect band gap in the visible and a direct band gap at a much higher energy, boron phosphide (BP) holds promise as an unconventional p-type transparent conductor. Previous experimental reports deal almost exclusively with epitaxial, nominally undoped BP films by chemical vapor deposition. High hole concentrations were often observed, but it is unclear if native defects alone can be responsible for it. Besides, the feasibility of alternative deposition techniques has not been clarified and optical characterization is generally lacking. In this work, we demonstrate reactive sputtering of amorphous BP films, their partial crystallization in a P-containing annealing atmosphere, and extrinsic doping by C and Si. We obtain the highest hole concentration reported to date for p-type BP ($5 \times 10^{20}$ cm$^{-3}$) using C doping under B-rich conditions. We also confirm that bipolar doping is possible in BP. An anneal temperature of at least 1000 $^\circ$C is necessary for crystallization and dopant activation. Hole mobilities are low and indirect optical transitions are much stronger than predicted by theory. Low crystalline quality probably plays a role in both cases. High figures of merit for transparent conductors might be achievable in extrinsically doped BP films with improved crystalline quality.
... [15][16][17][18][19] It has direct bandgap semiconducting properties with modulating features with the variation of stacking, interlayer distances, and external electric fields. 20,21 There are many experimental reports on the growth of BP. [22][23][24] Woo et al. reported that the optical bandgap of undoped and Sn-doped BP is ∼2.2 eV and 1.74 eV, respectively. 22 Padavala et al. suggested that for growing high-quality BP epitaxial films, AlN can be a perfect substrate. ...
... 20,21 There are many experimental reports on the growth of BP. [22][23][24] Woo et al. reported that the optical bandgap of undoped and Sn-doped BP is ∼2.2 eV and 1.74 eV, respectively. 22 Padavala et al. suggested that for growing high-quality BP epitaxial films, AlN can be a perfect substrate. 24 The n-type BP films show a high-electron mobility of 37.8 cm 2 /V s and the lowcarrier concentration of 3.15 × 10 18 cm −3 . ...
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Opto-electronic properties of boron phosphide–germanium carbide (BP/GeC), a new van der Walls hetero-bilayer (HBL) with all possible stacking patterns, are studied under the density functional theory originated frst-principles. The dynamical and chemical stabilities of the hetero-bilayer are confrmed by phonon spectra and binding energy. Among the dynamically stable HBLs, HBL 1 has the lowest binding energy with the smallest interlayer spacing of about 3.442 Å. Both values and natures (indirect or direct) of the electronic band structure are highly responsive to the stacking patterns. We have found that HBL 1 is indirect, while HBL 2 and HBL 3 become a direct bandgap at the K high symmetry point. All HBLs show type-II band alignment. Both compressive and tensile biaxial strains on the electronic properties of HBLs have been considered. All the HBLs become a direct bandgap for the compressive strain at 4% and 6%. We have also presented the optical property calculations on the HBLs, namely, the complex dielectric function and absorption properties, showing unique optical properties with signifcant absorption (5 × 105 cm−1 in HBL 2) in the whole solar spectra compared with their comprising monolayers. Moreover, the strain-dependent optical absorption coeffcients with varying photon wavelengths are calculated and the maximum value is attained to be about 6.5 × 105 cm−1 in HBL 2 at 4% compressive strain. Consequently, the optoelectronic properties we have explored in our proposed new hetero-bilayer systems can guide the experimental realization of the hetero-bilayers and effective use in the future photovoltaic applications.
... [15][16][17][18][19] It has direct bandgap semiconducting properties with modulating features with the variation of stacking, interlayer distances, and external electric fields. 20,21 There are many experimental reports on the growth of BP. [22][23][24] Woo et al. reported that the optical bandgap of undoped and Sn-doped BP is ∼2.2 eV and 1.74 eV, respectively. 22 Padavala et al. suggested that for growing high-quality BP epitaxial films, AlN can be a perfect substrate. ...
... 20,21 There are many experimental reports on the growth of BP. [22][23][24] Woo et al. reported that the optical bandgap of undoped and Sn-doped BP is ∼2.2 eV and 1.74 eV, respectively. 22 Padavala et al. suggested that for growing high-quality BP epitaxial films, AlN can be a perfect substrate. 24 The n-type BP films show a high-electron mobility of 37.8 cm 2 /V s and the lowcarrier concentration of 3.15 × 10 18 cm −3 . ...
Article
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ABSTRACT Opto-electronic properties of boron phosphide–germanium carbide (BP/GeC), a new van der Walls hetero-bilayer (HBL) with all possible stacking patterns, are studied under the density functional theory originated first-principles. The dynamical and chemical stabilities of the hetero-bilayer are confirmed by phonon spectra and binding energy. Among the dynamically stable HBLs, HBL 1 has the lowest binding energy with the smallest interlayer spacing of about 3.442 Å. Both values and natures (indirect or direct) of the electronic band structure are highly responsive to the stacking patterns. We have found that HBL 1 is indirect, while HBL 2 and HBL 3 become a direct bandgap at the K high symmetry point. All HBLs show type-II band alignment. Both compressive and tensile biaxial strains on the electronic properties of HBLs have been considered. All the HBLs become a direct bandgap for the compressive strain at 4% and 6%. We have also presented the optical property calculations on the HBLs, namely, the complex dielectric function and absorption properties, showing unique optical properties with significant absorption (5 × 105 cm−1 in HBL 2) in the whole solar spectra compared with their comprising monolayers. Moreover, the strain-dependent optical absorption coefficients with varying photon wavelengths are calculated and the maximum value is attained to be about 6.5 × 105 cm−1 in HBL 2 at 4% compressive strain. Consequently, the optoelectronic properties we have explored in our proposed new hetero-bilayer systems can guide the experimental realization of the hetero-bilayers and effective use in the future photovoltaic applications
... One of the most common ways to make BP is through bulk synthesis techniques, such as flux growth or solid-state reaction. 30,[76][77][78][79] Thin-film deposition of BP is almost invariably carried out by CVD of some kind, either metal-organic chemical vapor deposition (MOCVD), 73,80,81 or standard CVD, 68,[70][71][72]74,75,[82][83][84][85] or even plasma-enhanced CVD. 86 Other, less common deposition methods include vapor-liquid-solid growth, 87,88 thermal evaporation from powders in vacuum, 89 or sputtering in phosphine/Ar atmosphere. ...
... In the case of BP, the biggest experimental challenge is the highly inert nature of elemental boron, 78 which has led researchers to rely on deposition techniques that utilize more reactive forms of boron-specifically, diborane (B 2 H 2 ) in CVD-based processes. The drawback to this approach is the high toxicity of both diborane and phosphine, 86 which require special safety measures for use. ...
Article
Transparent conductive materials (TCMs) with high p-Type conductivity and broadband transparency have remained elusive for years. Despite decades of research, no p-Type material has yet been found to match the performance of n-Type TCMs. If developed, the high-performance p-Type TCMs would lead to significant advances in a wide range of technologies, including thin-film transistors, transparent electronics, flat screen displays, and photovoltaics. Recent insights from high-Throughput computational screening have defined design principles for identifying candidate materials with low hole effective mass, also known as disperse valence band materials. Particularly, materials with mixed-Anion chemistry and nonoxide materials have received attention as being promising next-generation p-Type TCMs. However, experimental demonstrations of these compounds are scarce compared to the computational output. One reason for this gap is the experimental difficulty of safely and controllably sourcing elements, such as sulfur, phosphorous, and iodine for depositing these materials in thin-film form. Another important obstacle to experimental realization is air stability or stability with respect to formation of the competing oxide phases. We summarize experimental demonstrations of disperse valence band materials, including synthesis strategies and common experimental challenges. We end by outlining recommendations for synthesizing p-Type TCMs still absent from the literature and highlight remaining experimental barriers to be overcome. © 2020 Society of Photo-Optical Instrumentation Engineers (SPIE).
... BP powders were also prepared from mixed boron and zinc phosphide in quartz tube at elevated temperature [8,19]. Single crystal BP was prepared by direct reaction of elemental boron and phosphorus with the use of Sn or Ni as catalyst [10,20]. Recently, mechanochemical methods for the synthesis of fine boron phosphide powders with the nominal purity higher than 97% was reported [21]. ...
... The final products of high purity BP were obtained. The prepared BP powders possessed four major typical diffraction peaks located at 2θ=34.2°, 39.7°, 57.4°and 68.5°which were assigned to (111), (200), (220) and (311) planes of cubic BP [8,20]. The very sharp XRD peaks with full-width half-maximum (FWHM) of 0.078°for (111) peak suggested very high crystallinity of our prepared BP. ...
Article
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In this work, microsized cubic BP particles was produced by vacuum-sealed solid state reaction. X-ray diffraction Rietveld refinement and x-ray photoelectron spectroscopy results indicate the prepared BP particles are highly crystalline and high purity. In-situ x-ray diffraction and Raman measurements under high pressure show the cubic BP particles possess high structural stability up to 36.0 GPa with high reversible structure recovering ability. Meanwhile, a high bulk modulus of 205(2) GPa and pressure derivative ${B}_{0}^{{\prime} }$ of 3.8(1) are obtained from in situ x-ray diffraction measurements. Grüneisen parameters of 1.01 and 1.17, and the pressure coefficient dω/dp = 4.07 and 4.57 cm⁻¹/GPa for LO and TO mode, respectively, are also deduced from Raman measurements under various high pressure.
... We have shown that the refractory boride, BP, can be synthesized using BI 3 as the source of boron. 24 Later, refractory metal borides such as HfB 2 and WB 2 have been prepared by reaction of the resistive heated metal wire with BBr 3 vapor. 11,12 In the current work, we extend BI 3 -assisted synthesis to rst row transition metals. ...
Article
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A facile and universal route for synthesizing transition metal borides has been developed by a reaction of boron triiodide (BI3) with elemental transition metals. This method employs relatively low synthesis...
... eV, ∼37.8 cm 2 /Vs of electron mobility, experimentally realized thin film growth, and high-optical absorption. [30][31][32]34 There are numerous experimental findings on BP growth. 34,35 The in-plane Young modulus and Poisson's ratio of monolayer BP are 135.6 ...
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Based on the motivation of the recent advancement of the van der Waals heterostructure (vdW HBL), we have studied the tunable optoelectronic properties of the two-dimensional (2D) boron phosphide–platinum di-oxide (BP/PtO2) heterostructure using dispersion corrected density functional theory (DFT). Six different stackings are considered to stack the 2D BP upon 2D PtO2 and are tested through DFT. Phonon spectra and binding energy calculation validate the dynamical and chemical stability of the constructed heterostructures. It is found that HBL1, HBL3, and HBL4 have type-II indirect band gaps of 0.001, 0.027, and 0.021 eV, respectively whereas the other HBLs 2, 4, and 5 show a semiconductor–metal transition. The variation in the interlayer distances, cross-plane electric field, and biaxial strain can effectively tune the bandgap, although type-II band alignment remains unaffected in all cases. A large built-in electric field, of ∼15 eV in electrostatic potential between the 2D structures and type-II band alignment of the HBL, suggests efficient separation of charges in all the HBLs. The bandgaps are highly responsive to the interlayer distances, electric field, and biaxial strain in the HBL. It is found that the bandgap increases under the application of compressive strain and an external electric field along the negative z-direction up to −0.4 V/Å. Interestingly, a semiconductor–metal transition occurs for tensile strain and the external electric field along the positive z-direction. All HBLs have efficient optical absorption in the visible and UV portions of the solar spectra, which is highly anticipated for optoelectronics applications. These unrivaled properties of the vdW BP/PtO2 HBL that we have explored make them a promising candidate for nano-electronic devices and infrared detector applications.
... Although of its broad favorable technological properties, cubic boron phosphide, BP, is notorious due to its difficult synthesis, thus preventing its numerous uses. Woo et al. prepare stable BP in three different methods [12]. Mogulkoc et al. investigate BP and show a direct bandgap with bilayers heterostructure and indirect for the tri-layer heterostructure. ...
Article
This work studies optical absorption in the zinc-blende boron-containing quantum dot (QD) structures. Eight structures are studied; two of them are the ternary BInP/GaP and BInP/BP. The others are BGaAsP/BP, BAlAsP/BAs, BInAsP/InP, BGaInAs/GaAs, BGaInP/BP, and BInAsP/GaP. The emission wavelengths of the structures cover a broad spectrum range from UV to near-infrared. The structures with BAs and BP barriers emit at 227,292nm. The structures BInAsP/InP and BGaInAs/GaAs have peak absorptions at 870nm and 920nm wavelengths, while ternary and quaternary structures with GaP barrier are at 720 and 1200nm. The structures with GaP barrier have importance in silicon device technology. The absorption peaks are arranged where the smallest energy difference between the transition subbands correspond to a higher absorption peak and are associated with a wide bandgap energy difference between the barrier and QD. For boron increment by 0.005 in the QD region, the peak absorption of BInP/GaP and BInP/BP in the TE mode have a wider red-shift (170 nm) in the peak wavelength. BGaAsP/BP has an absorption peak four orders higher than BAlAsP/BP. For of BInAsP/InP QD structure, the absorption spectrum is increased by more than four times under 0.0001-mole fraction increment of boron.
... Boron phosphide BP is a hard (Vickers hardness H V  30 GPa [1]) refractory (melting temperature at ambient pressure is 2840 K [2]) and low-compressible (300-K bulk modulus is 174 GPa [3]) wide bandgap (E g = 2.1 eV [4]) semiconductor with outstanding chemical and high-temperature stability that makes it a promising material for a wide range of applications [5]. Under ambient conditions, BP crystallizes in cubic sphalerite (F-43m) structure with boron and phosphorus tetrahedrally coordinated to each other. ...
Article
Microstructure of sphalerite (3C) boron phosphide, BP, produced by self-propagated high-temperature synthesis has been studied by high-resolution transmission electron microscopy. Along with numerous twins on the {111}3C plane, layers of wurtzite (2H) polymorphic modification and previously unknown for BP rhombohedral (9R) structure were found which indicates trimorphism of BP.
... It is a reliable, industrial method, which allows electronic-quality films to be grown at low temperatures over large areas. However, for BP layers, according to ref. [19], synthesis is difficult due to the difference in the reactivity of B and P. To solve this problem, it was proposed to use the plasma enhanced atomic layer deposition-like (pseudo PE-ALD) approach, in which the B and P atoms precursors are decomposed with the help of the RF plasma. ...
... This reliable industrial method allows the growth of films with high electronic quality at low temperatures over large areas. However, according to [6], for the BP layers, the synthesis is difficult due to the difference in the reactivity of B and P, which possibly explains the absence of reports on the development of a low-temperature BP formation technology. To solve this problem, it was proposed to use the plasma enhanced atomic layer deposition (PE-ALD) approach, in which the decomposition of the precursors of the B and P atoms are separated in time. ...
Article
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In this work the properties of the BP/Si heterojunction interface were investigated by capacitance methods, the deep levels transient spectroscopy method and admittance spectroscopy. Admittance spectroscopy did not detect any defects, but the deep level transient spectroscopy showed response with activation energy of 0.33 eV and capture cross-section σ n =(1-10)·10 ⁻¹⁹ cm ² and defect concentration (NT) is in the order of 10 ¹³ cm ⁻³ . This defect level is a trap for electron with position of 0.33 eV below the conduction band in region near the BP/Si interface.
... Boron phosphide BP is a hard (Vickers hardness H V  30 GPa [1]) refractory (melting temperature at ambient pressure is 2840 K [2]) and low-compressible (300-K bulk modulus is 174 GPa [3]) wide bandgap (E g = 2.1 eV [4]) semiconductor with outstanding chemical and high-temperature stability that makes it a promising material for a wide range of applications [5]. Under ambient conditions, BP crystallizes in cubic sphalerite (F-43m) structure with boron and phosphorus tetrahedrally coordinated to each other. ...
Preprint
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Microstructure of sphalerite (3C) boron phosphide, BP, produced by self-propagated high-temperature synthesis has been studied by high-resolution transmission electron microscopy. Along with numerous twins on the {111}3C plane, layers of wurtzite (2H) polymorphic modification and previously unknown for BP rhombohedral (3R) structure were found which indicates trimorphism of BP.
... In spite of its remarkable properties, the studies on this material are limited due the complications in the growing of single crystals [13,16]. In some investigations, depending on the preparation techniques and/or conditions, partially or fully amorphized BP samples were detected [5,7,[17][18][19]. However, no serious attention has been paid to understand the structure and properties of amorphous BP form so far. ...
Article
We generate a structural model of amorphous boron phosphide (BP) by quenching the melt via ab initio molecular dynamics calculations and compare it structurally and electrically with the crystal. We find that both phases of BP have a significantly different short-range order. Namely, the amorphous network presents strong chemical disorder and structural defects. P-atoms form only undercoordinated defects while B atoms present both undercoordinated and overcoordinated defects. The mean coordination number of B and P atoms is 4.17 and 3.69, correspondingly. Some of overcoordinated B atoms with chemical disorder yield the formation of pentagonal-pyramid-like motifs and a cage-like B10 cluster in the amorphous network. About 13 % volume expansion is observed by amorphization, probably due to the low-coordinated structural defects. The amorphous configuration is semiconductor as in the crystal but has a smaller energy band gap.
... Однако для слоев BP, согласно [13], синтез затруднителен из-за разницы в реакционной способности B и P, Количественные оценки свидетельствуют о примерно равном содержании атомов B и P в пределах погрешно-сти, связанной со столь малой толщиной слоя, которая не позволяет проводить точную оценку отклонения от стехиометрии. Наличие в спектре углеродной линии связано с содержанием углерода в измерительной камере и не может дать представления о его реальном содержании в слое. ...
Article
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For the first time, the possibility of forming boron phosphide layers by plasma-enhanced atomic-layer deposition at a temperature of 250 ° C has been shown. Also the possibility of their use as a selective hole contact to silicon for solar cell application has been experimentally demonstrated.
... Graphene like hexagonal boron phosphide (BP) with moderate energy gap and electron mobility of 10 6 cm 2 V − 1 s − 1 has been reported in single monolayer [17]. Synthesis efforts have been increasing despite many challenges [18][19]. Beyond certain bounds, 2D transition metal dichalcogens (TMDs) with wide variety of complementary properties have been synthesized [20][21][22][23][24]. ...
... Graphene like hexagonal boron phosphide (BP) with moderate energy gap and electron mobility of 10 6 cm 2 V − 1 s − 1 has been reported in single monolayer [17]. Synthesis efforts have been increasing despite many challenges [18][19]. Beyond certain bounds, 2D transition metal dichalcogens (TMDs) with wide variety of complementary properties have been synthesized [20][21][22][23][24]. ...
Article
In vdW heterostructures, the individual two-dimensional (2D) layers can have strong coupling and hence different electronic structures which makes it superior in electronic and optoelectronic applications. Here, based on density functional theory (DFT) calculations, we studied the interlayer rotation-angle dependent electronic structures and optoelectronic properties of BP-MoS2 vdW heterostructure. Within the range of 0–60°, the heterostructure shows tunable band alignment through type I and II with changes in interlayer rotation angle. Specifically, BP-MoS2 vdW heterostructures with rotation angles of 0°, 13.17°, and 60° were predicted to be type II and possess a significant potential drop across the interface to separate photoinduced-charge carriers, which is crucial for applications in photovoltaic and photocatalysis. Concurrently, BP-MoS2 heterostructures with rotation angles of 21.79°, 27.80°, and 38.21° were predicted to have type I band alignment and the inner band may serve as trap states for radiative photo-induced charge carriers which is also favorable for application in optoelectronic devices such as light emitting diodes (LEDs). Since the interlayer rotation is controllable during the synthesis of vdW heterostructures, our findings may greatly expand the application scope of engineered 2D materials for possible future applications in nanoelectronics.
... In the B x P y system, the cubic boron phosphide BP with the zincblende structure is a well-known compound with the hardness reported to be roughly the same as that of SiC 64 . In our calculations, the hardness of SiC and BP was found to be 33 GPa For these phases we found that ferromagnetic solutions are more stable than nonmagnetic. ...
Article
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Over the past decade, evolutionary algorithms, data mining, and other methods showed great success in solving the main problem of theoretical crystallography: finding the stable structure for a given chemical composition. Here, we develop a method that addresses the central problem of computational materials science: the prediction of material(s), among all possible combinations of all elements, that possess the best combination of target properties. This nonempirical method combines our new coevolutionary approach with the carefully restructured "Mendelevian" chemical space, energy filtering, and Pareto optimization to ensure that the predicted materials have optimal properties and a high chance to be synthesizable. The first calculations, presented here, illustrate the power of this approach. In particular, we find that diamond (and its polytypes, including lonsdaleite) are the hardest possible materials and that bcc-Fe has the highest zero-temperature magnetization among all possible compounds.
... As a sister semiconductor in the III-V material system, zinc-blende boron phosphide (BP) is structurally isotypic with c-BN, making it a highly promising superhard solid with a finite band gap. Although the first study on BP can be traced back to as early as the 1950s [10][11][12], only a handful of reports have since been published [1,[13][14][15][16][17]. This compound remains relatively unknown including its mechanical, electronic, and optical properties, mainly because synthesizing a high-quality BP sample is still challenging. ...
Article
New refractory hard materials with a favorable band gap are in high demand for the next-generation semiconductors capable of withstanding high temperature and other hostile environments. Boron phosphide (BP) is such an attractive candidate with exceptional properties; however, it has mainly been studied theoretically because of the difficulty in sample preparation. In this work, we report successful synthesis of large millimeter-sized single-crystal BP. The final product has a zinc-blende structure with a unique electronic structure and is optically transparent with a moderate band gap of ∼2.1 eV. Our experiments, in conjunction with ab initio simulations, reveal that the compound exhibits extraordinary strain stiffening and unusually high load-invariant hardness of ∼38 (3) GPa, which is close to the 40-GPa threshold for superhard materials, making BP the hardest among all known semiconductors. Based on the first-principles calculations, the fracture mechanisms in BP under tensile and shear deformations can be attributed to the formation of a metastable hexagonal phase. Further spectroscopic measurements indicate that an unusual electronic transition occurs at high pressures of ∼13 GPa, resulting in an asymptotically enhanced covalent bonding state. The pressure dependence of multiphonon processes is also determined by Raman measurement. In addition, our studies suggest a phonon-assisted photoluminescence process and evidence for the photon-pumped étalon effect at 707 nm.
... 39 Its direct bandgap is also significantly tunable through strain, 40 external electric field, and stacking pattern. 41 Bulk boron phosphide has been synthesized experimentally, 42,43 which suggests that 2D boron phosphide could be produced in the near future. In addition, 2D GaNbased vdW hetero-nanocomposites, such as GaN/MoS 2 , GaN/ MoSe 2 , GaN/WS 2 , GaN/WSe 2 , and GaN/ZnO, can form type-II band alignment and show good electronic and optical properties for photocatalyst and optoelectronic applications. ...
Article
Construction of van der Waals (vdW) nanocomposites can advance two-dimensional (2D) materials with desired properties and significantly widen their applications. Based on first-principles calculations, we verify that a gallium nitride/boron phosphide (GaN/BP) vdW nanocomposite is a direct-gap semiconductor with type-I band alignment. The nanocomposite shows significant optical properties in the visible and near-ultraviolet regions. Additionally, the bandgap, band edge positions, and optical absorption of the GaN/BP nanocomposite can be tuned by in-plane biaxial strains. A biaxial tensile strain with a strength of 3% can induce the type-II band alignment in the GaN/BP nanocomposite, which results in effective separation of the photo-generated charge carriers. Meanwhile, the application of biaxial strain can also significantly enhance the optical absorption of the GaN/BP nanocomposite in the near-infrared and visible regions. Furthermore, we show that the adjustment of interlayer coupling is also an effective way to modulate the electronic and optical properties of the GaN/BP nanocomposite. Our studies reveal the potential application of the GaN/BP nanocomposite in optoelectronic devices.
... Lately, phosphorene has drawn attention in part because of the size of its electronic band gap and its high hole-mobility, but its weak mechanical strength and chemical reactivity in air have limited its prospective applications [9]. Among the III-V group, bulk boron phosphide (BP) crystallizes in a zinc blende structure (non-layered compound) with an indirect band gap of 2.12 eV [10]. It shows high chemical stability and is resistant to chemical corrosion. ...
Article
Using density functional theory (DFT), we systemically studied the impact of various point defects on the structural, magnetic and electronic properties of graphene-like boron phosphide (h-BP) monolayer. The results showed that the defect-free monolayer structure retained semiconductor-like the respective bulk compound, but the band gap modifies its character from indirect to direct. The band gaps of h-BP sheet varied from 0.142/0.46 to 0.75/1.26 eV using PBE/HSE06 schemes due to the existence of Stone-Wales (SW) and antisites defects. Also, it should be noted that the defect-free monolayer showed metallic behavior with a noticeable ferromagnetism, by hosting a boron vacancy, and becomes an indirect semiconductor through single (P) and double (P-B) vacancies. Additionally, the stability of the favorable point defects has been predicted based on the cohesive and formation energies. We have collected STM images of the SW defect structure for upcoming experimental observations. This study may be useful when designing novel optoelectronic and magnetic devices that employ defective h-BP monolayers.
... 13 Similarly the electronic properties of the blue phosphorene/MGaN heterobilayer were investigated by tuning them with an external electric field in the scheme of DFT. 14 On the other hand, graphene-like monolayer boron phosphide (MBP) is also another promising material for electronic applications with its direct band gap being tunable with changes in the stacking pattern and an external electric field 3,15 together with superior carrier mobility. 16,17 Bulk boron phosphide was also synthesized by Woo et al. 18 and epitaxial growth on an aluminum nitride(0001)/sapphire substrate was reported by Padavala et al. 19 Recently, its heterostructure formation with monolayer blue phosphorus was investigated by Mogulkoc et al. which shows that the electronic and optical properties of the MBP/monolayer blue phosphorus heterostructure can be modified by changing the stacking pattern. 20 After the synthesis of graphene and other 2D monolayers, answers to a new question have been searched for by physicists as to whether stacking between different monolayers can enable the tuning the electronic structure and physical properties of the new structure. ...
Article
Motivated by the increasing number of studies on optoelectronic applications of van der Waals (vdW) heterostructures, we have investigated the electronic and optical properties of monolayer gallium nitride (MGaN) and boron phosphide (MBP) heterobilayers by using first-principle calculations based on density functional theory. We have ensured the dynamical stability of the structures by considering their binding energies and phonon spectra. We show that the magnitude and status (direct or indirect) of the band gap are strongly dependent on the stacking pattern of the heterobilayers. Furthermore, we have investigated the band splittings in the presence of an external electric field which show the effect of the field on the band alignment of the structure. We have also shown the band gap, charge redistributions and work function of the structures are highly dependent on the magnitude and direction of the electric field such that its magnitude yields indirect to direct band gap transitions around |E⊥| ∼ 0.7 V Å−1 at the Γ point and the order of the band gap is varied according to the direction of the electric field. Moreover, we examine optical properties of MGaN/MBP heterobilayers as part of DFT calculations. The band gap and work function being tunable with changes in the external field together with the prominent absorption over the UV range make the MGaN/MBP heterobilayer a feasible candidate for optoelectronic applications.
Article
Boron monoposphide (BP) has exclusive physical and chemical characteristics allowing it to be used in a variety of practical aspects. However, the usage of BP is limited as the single phase of boron monophosphide is notorious for its difficult synthesis. Moreover, the known methods of synthesis of BP with nanoscale sizes are challenging due to the usually required high temperatures and long synthesis durations. This paper reports the development of a simple, energy-efficient, straightforward Microwave activation synthesis method. Affordable raw materials were used to obtain pure single-phase BP nanopowder with narrow size distribution (70–90 nm) in a short time of synthesis (synthesis duration is 10 minutes).
Article
Controlling ultraviolet light at the nanoscale using optical Mie resonances holds great promise for a diverse set of applications, such as lithography, sterilization, and biospectroscopy. Access to the ultraviolet requires materials with a high refractive index and wide band gap energy. Here, the authors systematically search for such materials by computing the frequency‐dependent optical permittivity of 338 binary semiconductors and insulators from first principles, and evaluate their scattering properties using Mie theory. This analysis reveals several interesting candidate materials among which boron phosphide (BP) appears most promising. Then BP nanoparticles are prepared and it is demonstrated that they support Mie resonances at visible and ultraviolet wavelengths using both far‐field optical measurements and near‐field electron energy‐loss spectroscopy. A laser reshaping method is also presented to realize spherical Mie‐resonant BP nanoparticles. With a refractive index over three and low absorption losses in a broad spectral range spanning from the infrared to the near ultraviolet, BP is an appealing material for a broad range of applications in dielectric nanophotonics. High‐throughput computational screening of more than a thousand materials identifies boron phosphide (BP) as one of the most promising material for Mie‐resonant high‐refractive‐index nanoantennas operating in the visible and ultraviolet. Dark‐field and electron energy‐loss spectroscopy measurements on BP nanoparticles demonstrate size‐dependent Mie resonances.
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With an indirect band gap in the visible and a direct band gap at a much higher energy, boron phosphide (BP) holds promise as an unconventional p‐type transparent conductor. This work reports on reactive sputtering of amorphous BP films, their partial crystallization in a P‐containing annealing atmosphere, and extrinsic doping by C and Si. The highest hole concentration to date for p‐type BP (5 × 1020 cm−3) is achieved using C doping under B‐rich conditions. Furthermore, bipolar doping is confirmed to be feasible in BP. An anneal temperature of at least 1000 °C is necessary for crystallization and dopant activation. Hole mobilities are low and indirect optical transitions are stronger than that predicted by theory. Low crystalline quality probably plays a role in both cases. High figures of merit for transparent conductors might be achievable in extrinsically doped BP films with improved crystalline quality. Boron phosphide (BP) holds promise as an unconventional p‐type transparent conductor. This work employs carbon doping and annealing of reactively sputtered BP films to achieve bipolar conductivity and the highest p‐type carrier concentration reported to date. Modifications to the deposition process are suggested to obtain better transparency and higher hole mobilities.
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Controlling ultraviolet light at the nanoscale using optical Mie resonances holds great promise for a diverse set of applications, such as lithography, sterilization, and biospectroscopy. However, Mie resonances hosted by dielectric nanoantennas are difficult to realize at ultraviolet wavelengths due to the lack of both suitable materials and fabrication methods. Here, we systematically search for improved materials by computing the frequency dependent optical permittivity of 338 binary semiconductors and insulators from first principles, and evaluate their potential performance as high refractive index materials using Mie theory. Our analysis reveals several interesting candidate materials among which boron phosphide (BP) appears particularly promising. We then prepare BP nanoparticles and demonstrate that they support Mie resonances at visible and ultraviolet wavelengths using both far-field optical measurements and near-field electron energy-loss spectroscopy. We also present a laser reshaping method to realize spherical Mie-resonant BP nanoparticles. With a refractive index above 3 and low absorption losses, BP nanostructures advance Mie optics to the ultraviolet.
Article
BP powders with high thermal conductivity were synthesized by a facile molten salt method and used as thermal conductive fillers to prepare nanofibrillated cellulose composite film with higher thermal conductivity.
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Nonlinear optical materials have gained immense scientific interest in the recent times owing to their vast applications in various fields. Continuous strides are made to design and synthesize materials with large nonlinear optical response and high thermodynamic stability. In this regard, we present here bi-alkali metal doping on boron phosphide nanocage as a new strategy to design thermodynamically stable materials with large nonlinear optical response. The geometric, thermodynamic, electronic, optical and nonlinear optical properties of complexes are explored through density functional theory (DFT) simulations. The doping of alkali metal atoms introduces excess of electrons in the host (B12P12) nanocage. These electrons contribute towards the formation of new HOMOs, which reduce the HOMO–LUMO gaps of the designed complexes. The HOMO–LUMO gaps of the designed complexes range from 0.63 eV to 3.69 eV. The diffused excess electrons also induce large hyperpolarizability values in the complexes i.e. up to 4.0 × 104au. TD-DFT calculations have been performed for crucial transition states and UV–VIS analysis. Non-covalent interaction (NCI) along with quantum theory of the atoms in molecules (QTAIM) analyses are carried out to understand the bonding interactions between alkali metal atoms and B12P12 nanocage. All the obtained results suggest that bi-alkali metal doped nanocages are exceptionally stable materials with improved NLO response.
Article
Surface functionalization is one of the useful techniques for modulating the mechanical and electronic properties of two-dimensional systems. In the present study, we investigate the structural, elastic, and electronic properties of hexagonal boron phosphide monolayer functionalized by Br and Cl atoms using first-principles predictions. Once surface-functionalized with Br/Cl atoms, the planar structure of BP monolayer is transformed to the low-buckled lattice with the bucking constant of about 0.6 Å for all four configurations of functionalized boron phosphide, i.e., Cl–BP–Cl, Cl–BP–Br, Br–BP–Cl, and Br–BP–Br. The stability of functionalized BP monolayers is confirmed via their phonon spectra analysis and ab initio molecular dynamics simulations. Our calculations indicate that the functionalized BP monolayers possess a fully isotropic elastic characteristic with the perfect circular shape of the angle-dependent Young's modulus and Poisson's ratio due to the hexagonal symmetry. The Cl–BP–Cl is the most stiff with the Young's modulus C2D = 43.234 N m−1. All four configurations of the functionalized boron phosphide are direct semiconductors with a larger band gap than that of a pure BP monolayer. The outstanding stability, isotropic elastic properties, and moderate band gap make functionalized boron phosphide a very intriguing candidate for next-generation nanoelectromechanical devices.
Article
Single-crystal boron phosphide (BP), a high-temperature semiconductor, is prepared by a eutectic melting method. Large BP single crystals (>1 mm) are synthesized at high pressure and high temperature (5.0 GPa and 3000 °C). Their growth mechanism is analyzed. Ultraviolet–visible spectroscopy and thermogravimetry/differential thermal analysis show that BP is an indirect semiconductor (2.01 eV) and has excellent thermal stability (>1200 °C). Success in the synthesis of good BP crystals offers a huge opportunity to determine their intrinsic properties and will also stimulate more research on their performance as semiconductors.
Article
The doping of boron phosphide (BP) with manganese as magnetic impurity at different concentrations provides metallic ferromagnetic materials B[Formula: see text]Mn x P at ([Formula: see text], 0.125, 0.0625). Their structural and electronic properties are calculated by the first-principle spin-density functional theory (DFT) within the framework of the Wu–Cohen generalized gradient approximation (WC-GGA). The DMSs BP originated from doping manganese contributed in SP3 hybridization of tetrahedral crystal field caused by the surrounding of four phosphorus anions. These compounds are not half-metallic but exhibit a poorly metallic ferromagnetic nature, the cause is due to the highly covalent chemical bond of BP. The B[Formula: see text]Mn x P are metallic ferromagnetic materials and are not to be intended for spintronic industry.
Article
We proposed a boron−phosphorus monolayer (BP-ML) and investigated its gas sensing properties by density functional theory including the van der Waals dispersion correction term. Electronic property analysis reveals that BP-ML is a semiconductor with an indirect bandgap of 0.54 eV. The adsorption energy calculations of nitrogen-containing gases (NCGs) such as N 2 O, NO 2 , NH 3 , and NO show that these gases are physisorbed on the BP-ML surface. Among the studied NCGs, the NO 2 molecule exhibits a relatively higher charge (0.43 e), which further confirms a robust charge transfer and more reactivity with the BP-ML surface. The work function of BP-ML increases by NO 2 adsorption from 4.75 to 5.13 eV, while it decreases with adsorption of other NCG molecules. We have noticed that NO 2 shows a considerably short recovery time of 2.21 s at T = 300 K, strongly referring to the multitime reusable nanosensor characteristic of the BP-ML surface. Additionally, the transport properties of the BP surface for the real-time sensing application are investigated by using the nonequilibrium Green's function (NEGF) approach. The current−voltage (I−V) characteristics indicate a significant (moderate) change along the armchair (zigzag) direction when the NO 2 molecule is adsorbed on the BP-ML surface. These findings suggest that BP-ML surface-based sensors are highly sensitive for the detection of NO 2 molecules with short recovery time.
Article
Cubic boron compounds (c-BN, c-BP, and c-BAs) are emerging semiconductor materials with extraordinary chemical and physical properties, e.g., record-high thermal conductivity. Because of these, they have attracted increased interest for applications in heat management and electronics. However, many fundamental properties especially for c-BP and c-BAs remain poorly understood. Herein, we report a systematic first-principles study of the important physical properties of boron compounds, including elastic constants, mechanical properties, and deformation behavior under tensile and shearing (pure shear and Vickers indentation shear) loads. The stress-strain relations show isotropic elastic behavior at a small strain and strong anisotropic responses with varied peak stresses along different tensile direction and shear system at a larger strain. In particular, we observe a large disparity between the tensile and shear strengths for c-BP and c-BAs due to shearing load-induced metallization and phonon softening. We examine the deformation process in terms of bond-breaking to understand the microscopic origin and impact on the strength of the materials. We show that both c-BP and c-BAs are not superhard materials but they offer a balance between hardness, synthesis, and sustainability that has been an issue for both c-BN and diamond for applications.
Article
Density functional theory (DFT) calculations have been performed to investigate adsorption and incorporation of arsenic on the boron phosphide (1 1 1) surface. We considered different arsenic coverages. Dimers (1/2 ML), trimers (¾ ML), and atomic wires (1 ML) are formed upon increasing As coverage. However, at full monolayer, the most relevant result is the hexagonal boron phosphide (h-BP) monolayer formation, a 2D graphene-like structure. The h-BP monolayer phonon dispersion shows only positive frequencies indicating dynamical stability. At the same time, this suggests the possible h-BP monolayer exfoliation (desorption energy of only 0.26 eV/1x1) because it is weakly attached to the substrate by van der Waals interactions, as demonstrated by the non-covalent interaction index analysis. Electronic band structures indicate that this 2D layer may support direct transitions, making it useful for applications in electronic devices. The density of states and projected density of states complement the electronic properties analysis. We encourage the experimental realization of h-BP by As incorporation on BP surfaces.
Article
To develop highly efficient electrochemical catalysts for N2 fixation is important to sustainable ambient NH3 production through the N2 reduction reaction (NRR). Herein, we demonstrate the development of vanadium phosphide nanoparticle on V foil as a high-efficiency and stable catalyst for ambient NH3 production with excellent selectivity. The high Faradaic efficiency of 22% with a large NH3 yield of 8.35 × 10−11 mol·s−1·cm−2 was obtained at 0 V vs. the reversible hydrogen electrode in acid solution, superior to all previously studied V-based NRR catalysts. Density functional theory calculations are also utilized to have an insight into the catalytic mechanism.
Article
Inspired by the huge surge of interests devoted to the nanoelectronic applications of van der Waals (vdW) heterostructures, we have examined the structural and electronic properties of the heterostructure systems composed of single-layer boron phosphide (BP) and molybdenum disulfide (MoS2) monolayers using the density functional theory calculations. Various stacking patterns were considered to form favorable hybrid systems consisting of MoS2 and BP monolayers. In this work, we confirmed the stability of the constructed heterostructures by calculating the binding energies. Our results demonstrated that all the considered patterns of MoS2/BP heterostructures exhibited semiconducting electronic properties. Small band gaps are created around the Fermi level for all the stacking arrangements, which are lower than the band gaps of bare MoS2 and BP monolayers. Our designed MoS2/BP vdW heterostructures may be a prominent candidate for applications in future nanoscale electronic devices.
Article
Boron phosphide nanosheets were synthesized by direct chemical reaction of B2H6 and PCl3 at ambient temperature, facilitated by use of plasma in an ionic liquid. The material possessed excellent specific capacity of 179.3 F g⁻¹, large specific surface area (221.7 m² g⁻¹), and an average thickness of 8.422 nm. It can serve as an electrode material for capacitive deionization to extract U(VI) ions from aqueous solution at concentrations ranging from 0.05 to 130 mg L⁻¹, with a maximum adsorption capacity of 2584 mg g⁻¹. The excellent performance of these boron phosphide nanosheets is mainly due to their special structural features and ability to strongly coordinate with uranium, which facilitates the electrosorption process. This material also demonstrated superior selective adsorption characteristics for U(VI) ions over other competing metal ions (Sr²⁺, Ba²⁺, VO3⁻, Cr³⁺, Ca²⁺, Co²⁺, Cu²⁺, Mn²⁺, Mg²⁺, Ni²⁺, Fe³⁺, Na⁺, and K⁺) present in natural seawater. Boron phosphide nanosheets offer potential as a novel and potent electrode material to extract uranium from seawater using capacitive deionization technology.
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Flux crystal growth has been widely applied to explore new phases and grow crystals of emerging materials. To accommodate the needs of high-quality single crystals, the flux crystal growth should be reliable, controllable, and predictable. The selections of suitable flux and growth conditions remain empirical due to the lack of systematic investigation especially for reactions, which involve highly volatile components, such as P and As. Considering the flux elements, often the system in question is a quaternary or a higher multinary system, which drastically increases complexity. In this manuscript, on the examples of flux growth of phosphides and arsenides, guidelines of flux selections, existing challenges, and future directions are discussed. We expect that the field will be further developed by applying in situ techniques and computational modeling of the nucleation and growth kinetics. Additionally, leveraging variables other than temperature, such as applied pressure, will make flux growth a more powerful tool in the future.
Article
In this study, we investigate the adsorption properties of Fe, Co, Ni, Cu, Zn, In, Tl, Ar atoms on hexagonal boron phosphide monolayer (h-BP) using density functional theory within both GGA and LDA functionals. Bare h-BP is a direct gap semiconductor with planar structure. The adsorption of the atoms on h-BP exhibits a large variety of electronic properties like semiconducting, metallic, and half-metallic states. Fe- and Ni-adsorbed h-BPs show semiconducting character with decreased band gaps. Ni atom is strongly adsorbed on the surface giving largest adsorption energy observed in this work. Fe-adsorbed system is a semiconducting ferromagnet with 1.95 μB magnetic moment. Co adsorption results in a half-metallic behaviour with 1.00 μB net magnetic moment and a perfect spin polarisation at Fermi level. Cu, In, and Tl adsorbed h-BP systems show metallic character. The results obtained show that h-BP surface can be functionalised via adsorption of related single atoms and can be suitable for various applications in optoelectronics and spintronics.
Article
Cubic boron phosphide (BP) is an indirect band gap semiconductor with the band gap of 2.0 eV and promising for a highly stable photocatalyst to produce hydrogen from water under visible light irradiation. Here, we performed a comprehensive study on the energy level structure and photocatalytic activity of BP nanocrystals (NCs) in the quantum confinement regime (< 5 nm in diameter). First, we calculated the electronic structure of cubic BP NCs up to 2.8 nm in diameter, hexagonal BP nanoflakes and cubic/hexagonal BP nanostructures by the density functional theory and the time-dependent density functional theory. We then synthesized BP NCs with 2 to 13 nm in diameters and performed detailed structural analyses and optical measurements. The photocatalytic bleaching experiments for dye molecules under visible light irradiation revealed that the bleaching rate depends strongly on the size of BP NCs; the increase in the band gap of BP NCs by the quantum size effects (QSE) enhanced the photocatalytic activity. The band gap increase by the QSE also enhanced the rate of photocatalytic hydrogen evolution in water.
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Computational materials discovery is a booming field of science, which helps in predicting new unexpected materials with optimal combinations of various physical properties. Going beyond the targeted search for new materials within prespecified systems, the recently developed method, Mendelevian search, allows one to look for materials with the desired properties across the entire Periodic Table, indicating possibly superhard (or other) materials that could be obtained experimentally. From this viewpoint, we discuss the recently developed methods for crystal structure prediction and empirical models of Vickers hardness and fracture toughness that allow fast screening for materials with optimal mechanical properties. We also discuss the results of the computational search for hard and superhard materials obtained in the last few years using these novel approaches and present a “treasure map” of hard and superhard materials, which summarizes known and predicted materials and points to promising future directions of superhard materials discovery.
Article
As a carbon-neutral alternative to the Haber-Bosch process, electrochemical N2 reduction enables environment-friendly NH3 synthesis at ambient conditions but needs active electrocatalysts for the N2 reduction reaction (NRR). In this communication, we report on the first experimental demonstration that non-metal boron phosphide (BP) nanoparticles can be used as a high-efficiency catalyst for the ambient electrohydrogenation of N2 to NH3 with excellent selectivity. In 0.1 M HCl, this catalyst offers a large NH3 yield of 26.42 μg h–1 mg–1cat. and a high Faradaic efficiency of 12.7% at –0.60 V vs. reversible hydrogen electrode, much superior to reported B catalysts. Such enhancement is attributed to that P in BP further weakens the N≡N bond while simultaneously strengthening the B-N bond and favors the exposure of more active sites for the NRR catalysis, which is supported by density functional theory calculations.
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Zinc blende boron arsenide (BAs), boron phosphide (BP), and boron nitride (BN) have attracted significant interest in recent years due to their high thermal conductivity (Λ) predicted by first‐principles calculations. This research reports the study of the temperature dependence of Λ (120 K < T < 600 K) for natural isotope‐abundance BP and isotopically enriched ¹¹BP crystals grown from modified flux reactions. Time‐domain thermoreflectance is used to measure Λ of sub‐millimeter‐sized crystals. At room temperature, Λ for BP and ¹¹BP is 490 and 540 W m⁻¹ K⁻¹, respectively, surpassing the values of conventional high Λ materials such as Ag, Cu, BeO, and SiC. The Λ of BP is smaller than only cubic BN, diamond, graphite, and BAs among single‐phase materials. The measured Λ for BP and ¹¹BP is in good agreement with the first‐principles calculations above 250 K. The quality of the crystals is verified by Raman spectroscopy, X‐ray diffraction, and scanning transmission electron microscopy. By combining the first‐principles calculations and Raman measurements, a previously misinterpreted Raman mode is reassigned. Thus, BP is a promising material not only for heat spreader applications in high‐power microelectronic devices but also as an electronic material for use in harsh environments.
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Over the past decade, evolutionary algorithms, data mining and other methods showed great success in solving the main problem of theoretical crystallography: finding the stable structure for a given chemical composition. Here we develop a method that addresses the central problem of computational materials science: prediction of material(s), among all possible combinations of all elements, that possess the best combination of target properties. This non-empirical method combines our coevolutionary approach with carefully restructured "Mendelevian" chemical space, energy filtering, and Pareto optimization to ensure that the predicted materials have optimal properties and a high chance to be synthesizable. First calculations, presented here, illustrate the power of this approach.
Article
The van der Waals (vdW) heterostructures are emerging as promising structures for future possible optoelectronic devices. Motivated by the recent studies on vdW heterostructures with their fascinating physical properties, we investigate the electronic and optical properties of boron phosphide/blue phosphorus heterostructures in the framework of density functional theory (DFT) and tight-binding (TB) approximations. We analyze the variation of the energy band gap, the characteristics of the energy band diagram, charge redistribution by stacking and the electrostatic potential along the perpendicular direction. The dynamical stability of these structures is ensured by the phonon spectra. We show that trilayer heterostructures of boron phosphide/bilayer blue phosphorus are in-direct band gap semiconductors while heterobilayers have a direct band gap at the K point. Moreover, we examine the optical properties of monolayer boron phosphide and heterostructures as part of DFT calculations. We conclude that the heterostructures have remarkable optical absorption over the UV range together with being transparent to the visible spectrum, and may be a prominent material for future optoelectronic devices.
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An effective method of synthesis of tin phosphide Sn4P3 starting from metallic tin and amorphous red phosphorus by a low-temperature (200°C) solvothermal reaction in ethylenediamine is offered. The key parameters of this process – duration, temperature, and the ratio of initial components (Sn/P) are studied. The structure, phase composition, and morphology of the products are investigated using powder X-ray diffraction and scanning electron microscopy. Different synthetic ways for tin phosphide are discussed and compared with the proposed one. The mechanism of solvothermal preparation of tin phosphide in ethylenediamine is discussed. It is shown that the proposed solvothermal method opens up the possibility of preparing other metal-rich phosphides.
Article
Four methods of preparation of cubic boron phosphide, BP, are described. The chemical and physical properties of BP and BAs are reported. The formation of lower phosphides and arsenides is noted.
Article
Crystalline Al1-xBxPSi3 alloys (x=0.04-0.06) are grown lattice-matched on Si(100) substrates by reactions of P(SiH3)3 and Al(BH4)3 using low pressure CVD. The materials have been characterized for structure, composition, phase purity and optical response by spectroscopic ellipsometry, high resolution XRD, XTEM, EELS and EDS, which indicate the formation of single-phase monocrystalline layers with tetrahedral structures based on AlPSi3 parent phase. The latter comprises interlinked AlPSi3 tetrahedra forming a cubic lattice in which the Al-P pairs are imbedded within a diamond structured Si matrix as isolated units. Raman scattering of the Al1-xBxPSi3 films supports the presence of substitutional B in place of Al and provides strong evidence that the boron is bonded to P in the form of isolated pairs, as expected on the basis of the AlPSi3 prototype. The substitution of small size B atoms is facilitated by the stabilizing effect of the parent lattice, and it is highly desirable for promoting full lattice matching with Si as required for Si-based solar cell designs. The substitution of B also increases the bond-length disorder leading to a significantly enhanced absorption relative to Si and AlPSi3 at E <3.3 eV which may be beneficial for PV applications. Analogous reactions of As(SiH3)3 with Al(BH4)3 produce Al1-xBxAsSi3 crystals in which the B incorporation is limited to doping concentrations at 1020 atoms/cm3. In both cases the classical Al(BH4)3 acts as an efficient delivery source of elemental Al to create crystalline group IV-III-V hybrid materials comprising light, earth abundant elements with possible application in the fields of Si-based technologies and light-element refractory solids.
Article
A new method of producing boron phosphide (BP) submicron powders by a self-propagating high-temperature reaction between boron phosphate and magnesium in the presence of an inert diluent (sodium chloride) has been proposed. Bulk polycrystalline BP with microhardness of H V = 28(2) GPa has been prepared by sintering the above powders at 7.7 GPa and 2600 K.
Article
The fourth version of the program package WinCSD is multi-purpose computer software for crystallographic calculations using single-crystal and powder X-ray and neutron diffraction data. The software environment and the graphical user interface are built using the platform of the Microsoft .NET Framework, which grants independence from changing Windows operating systems and allows for transferring to other operating systems. Graphic applications use the three-dimensional OpenGL graphics language. WinCSD covers the complete spectrum of crystallographic calculations, including powder diffraction pattern deconvolution, crystal structure solution and refinement in 3 + d space, refinement of the multipole model and electron density studies from diffraction data, and graphical representation of crystallographic information.
Article
DOI:https://doi.org/10.1103/PhysRevLett.4.282
Article
Raman spectra of wurtzite AℓN and zincblende BN and BP were excited by a He-Ne laser (6328A). The long wavelength Raman lines determined are the following: (i) For AℓNA1 (TO) = E1(TO) = 667 cm−1, A1 (LO) = E1 (LO) = 910 cm−1 and E2 = 665 cm−1; (ii) For cubic BN TO = 1056 cm−1 and LO = 1304 cm−1; (iii) For BP only one line was observed at 829 cm−1. The ratio of LO to TO intensities is discussed briefly.RésuméDie durch einen He-Ne laser angereten Raman Spektren von AℓN (Wurtzit) und BN und BP (Zincblende) wurden gemessen. Die folgenden Raman Linien wurden gefunden; (1) Für AℓNA1 (TO) = E1 (TO) = 667 cm−1, A1 (LO) = E1 (LO) = 910 cm−1 und E2 = 655 cm−1; (2) für kubisches BN TO = 1056 cm−1 und LO = 1304 cm−1; (3) für BP wurde nur eine Linie bei 829 cm−1 beobachtet. Das Intensitätsverhältnis zwischen LO und TO wird kurz diskutiert.
Article
Boron phosphide has been synthesized from the elements at pressures and temperatures above 20 kbar and 1200 °C. The growth rate of crystals has been determined as a function of temperature and pressure. An activation energy of 49.27 kcal/mole has been obtained for the process. Crystals of boron phosphide have further been synthesized from the B-O-P system using mixtures of (1) boron, phosphorus and boron oxide; (2) boron and boron phosphate; and (3) boron and phosphorus pentoxide. Optical and scanning electron micrographs reveal details of the crystal morphology. Transmission measurements indicate the fundamental absorption edge of BP to lie at around 5 eV.
Article
The thermal diffusivity of a well-characterized boron phosphide (BP) single-crystal wafer made by a chemical vapor deposition process was measured by a unique ring-flash light method. Thermal conductivity calculated from the products of thermal diffusivity, specific heat capacity, and density of the wafer yields a high thermal conductivity of 4.0 W cm−1 deg−1 at room temperature, and shows a pronounced temperature dependence due to phonon scattering. Boron phosphide is a promising material for heat-sink substrates for semiconductor devices.
Article
Nanocrystalline boron phosphide (BP) was successfully synthesized at low temperature (400 degreesC) by a simple reaction between PCl3 and NaBF4 using Na as reductant. X-ray powder diffraction patterns indicated that the resultant was cubic BP with a lattice constant a=4.533 Angstrom. Transmission electron microscopy revealed that the crystals were composed of spherical particles with the diameter of 80 nm or so and lots of worm-like rods. The possible formation mechanism was also investigated. (C) 2004 Elsevier B.V. All tights reserved.
Article
The crystal growth of boron phosphide, BP, has been investigated using two approaches: (i) the addition of phosphorus to a boron-nickel or boron-copper melt, and (ii) the recrystallization of boron phosphide from a nickel phosphide or copper phosphide solution in a temperature gradient. To determine the optimum conditions for the growth processes, the solubility of boron phosphide in nickel phosphide (Ni//1//2P//5) and copper subphosphide (Cu//3P) was determined over a wide temperature range. The solubility of boron phosphide in nickel phosphide was found to be higher than that in copper phosphide. The temperature gradient recrystallization of boron phosphide from nickel phosphide at 1200 C has produced larger crystals. The solution-grown crystals were in the form of hoppers and platelets with platelets dominating. Because of its large energy gap, boron monophosphide has potential applications for high temperature devices and for visible light-emitting devices.
Article
The crystal structure of phosphorus trifluoride-tris(dinuoroboryl)borane, B4F6 · PF3, has been determined by an X-ray diffraction study of single-crystal specimens. The orthorhombic unit cell, space group Pnma, with a = 13.893 ± 0.005 Å, b = 10.578 ± 0.005 Å, and c = 6.075 ± 0.005 Å, contains four formula units. The calculated density is 1.82 g/cm3. The structure was solved by statistical methods and refined by full-matrix least squares to a conventional R of 9.3% for 703 data collected by counter methods (6.7% for the 603 nonzero data). The molecule consists of a central boron atom, tetrahedrally bonded to three BF2 groups and the PF3 group in such a way that the molecule has approximately 3m (C3v) point symmetry, one mirror of which is required by the crystal symmetry. Distances found (uncorrected for thermal motion) are: B-F, 1.305 Å; B-B, 1.68 Å; B-P, 1.825 Å; P-F, 1.51 Å (all ±0.015 Å).
Article
The crystal structure of SnP can be described with a trigonal unit cell of dimensions a = 4.3922(7) and c = 6.040(3) Å and spacegroup P3m1, Z = 2. The structure is layered and similar to the C6 structure from which it can be formally derived by substitution of the octahedrally coordinated atoms with atom pairs. The tin atoms form a hexagonal packing. The phosphorus atoms are situated as P2 pairs filling octahedra in every second tin layer. The closest Sn-Sn distance is 3.482(2) Å. The distances between the atoms of the P2 pairs are 2.2 Å, and the closest Sn-P distances are 2.62-2.67 Å. Present address: The Central Board of National Antiquities, Technical Institution, Box 5405, S-114 84 Stockholm, Sweden.
Article
The mode Grüneisen parameters of the LO and TO Raman phonons of AlN, BN, and BP, and the dependence of e*T on lattice constant have been measured by Raman scattering in a diamond anvil cell. The results for e*T are interpreted by means of pseudopotential calculations of e*T versus lattice constant.
Article
Trirubidium Diarsenidoborate, Rb3BAs2 and Trirubidium Diphosphidoborate, Rb3BP2 are isotypic to K3BP2, and can be described as derivatives of the layered hexagonal AlB2 type, but with some vacancies at Al sites and interstitials (B between P or As atoms).
Article
THE application of the semi-conducting properties of germanium and silicon in devices of great technical importance has in recent years stimulated interest in the III–V compounds1. Compounds of the group III elements aluminium, gallium and indium with the group V elements phosphorus, arsenic and antimony have the cubic zinc-blende structure, which is closely related to the diamond structure of the group IV elements carbon, silicon, germanium and grey tin. The nitrides of aluminium, gallium and indium have the hexagonal wurtzite structure. The nitride of boron, the lightest of the group III elements, has a graphite-like hexagonal layer lattice.
Article
The single crystal growth of boron phosphide (BP) by employing the high pressure flux method and chemical vapor deposition (CVD) process is described together with characterization of the prepared BP and its electrical, thermal, semiconducting, and electrochemical properties. BP single crystals prepared by the high pressure flux method contain copper used as the flux, but they are promising for photocathode materials. BP single crystalline wafers prepared by the CVD process using Si wafer substrate contained autodoped silicon with the concentration of 1018−1020 atoms·cm−3, depending on the growth temperature and the substrate plane. The Si atoms which act as acceptors are incorporated at phosphorus sites in BP. The lattice constants determined by the Bond method explain the conduction type of BP. Some electronic transport properties such as donor and acceptor levels and lattice scattering process before and after thermal neutron experiments are clarified. The thermal conduction is limited by three-phonon processes. The formation of defects by thermal neutron irradiation and that of structural disorder by ion-irradiation are mentioned. Schottky diodes consisting of n–BP and Sb or n–BP and Au, which are denoted as n–BP–Sb and –Au, respectively, show excellent characteristics, and their barrier heights are independent of metals and two-thirds of energy bandgap, expected from the surface-state model. Finally, recent results on thermoelectric properties of sintered specimens are mentioned.
Article
The crystal structure of Sn3P4, a long-known tin phosphide, has been determined. It crystallizes in the trigonal space group R3̄m with unit-cell parameters a = 4.4315(1) Å and c = 28.393(1) Å (Z = 3). The crystal structure of Sn3P4 is disordered. It consists of alternating layers of phosphorus and tin atoms that are combined into five-layer blocks and propagate along the c-axis. The major structural feature is the disordered orientation of the P24– dumbbells, which link the tin atoms. The latter possess two types of coordination. One third of the tin atoms reside inside the block and are octahedrally coordinated by phosphorus atoms. The rest of the tin atoms confine the block and possess a [3 + 3] environment made up of three close phosphorus neighbors and three rather distant (3.4 Å) tin atoms of the adjacent block. The coordination of the tin atoms is confirmed by 119Sn Mössbauer spectroscopy. The electron diffraction and high-resolution electron microscopy data reveal ordered regions at the microscopic level, which do not result in any superstructure formation for the bulk sample. Physical property measurements show that Sn3P4 is a narrow-gap semiconductor. Upon cooling to 150 K it undergoes a remarkable transition from n-type conduction with electrons as charge carriers to p-type conduction with holes as charge carries. Despite the large amount of disorder in the crystal structure, Sn3P4 has a relatively high thermal conductivity of about 8 W m–1 K–1.
Article
Thick, single crystalline boron phosphide (BP) wafers (∼200–300 μm) grown by the chemical vapor deposition technique were characterized by the measurements of lattice constants by the Bond method and electrical properties by the Van der Pauw method. Two types of Schottky barrier diodes, i.e., n‐BP‐Sb and p‐BP‐Au, were fabricated. The n‐BP‐Sb diode has the highest reverse voltage of 5 V and a barrier height of 1.4 eV, while those of the p‐BP‐Au diode are 1 V and 1.2 eV. These results suggest that device application of BP is promising.
Article
We present synthesis, crystal structure, hardness, and IR/Raman and UV/Vis spectra of a new compound with the mean composition LiB(12) PC. Transparent single crystals were synthesised from Ga, Li, B, red phosphorus and C at 1500 °C in boron nitride crucibles welded in Ta ampoules. Depending on the type of boron used for the synthesis we obtained colourless, brown and red single crystals with slightly different P/C ratios. Colourless LiB(12) PC crystallizes orthorhombic in the space group Imma (No. 74) with a=10.188(2) Å, b=5.7689(11) Å, c=8.127(2) Å and Z=4. Brown LiB(12) P(0.89) C(1.11) is very similar, but with a lower P content. Red single crystals of LiB(12) P(1.13) C(0.87) have a larger unit cell with a=10.4097(18) Å, b=5.9029(7) Å, c=8.2044(12) Å. EDX measurements confirm that the red crystals contain more phosphorus than the other ones. The crystal structure is characterized by a covalent network of B(12) icosahedra connected by exohedral BB bonds and PP, PC or CC units. Li atoms are located in interstitials. The structure is closely related to MgB(7) , LiB(13) C(2) and ScB(13) C. LiB(12) PC fulfils the electron counting rules of Wade and also Longuet-Higgins. Measurements of Vickers micro-hardness (H(V) =27 GPa) revealed that LiB(12) PC is a hard material. The optical band gaps obtained from UV/Vis spectra match the colours of the crystals. Furthermore we report on the IR and Raman spectra.
Article
Thin films of polycrystalline boron phosphide (BP) are obtained by using conventional thermally activated chemical vapor deposition. BBr3 and PBr3 are used as reactants and BP is formed at 940°C in a H2 environment. A rough black layer is obtained on alumina substrates. All films are n-type with a high donor density. (Photo-) current-voltage curves are presented. The transient photocurrent response and the presence of a substantial photocurrent at subbandgap illumination strongly suggests the presence of a high density of surface states. Impedance spectra of the unilluminated electrode could be modelled adequately with an equivalent circuit. Numerical values of the space charge capacitance were obtained at anodic potentials. The flatband potential was determined from Mott-Schottky plots, and appeared to depend strongly on the electrolyte pH. The flatband potential of BP is (+0.182 – 0.073 pH) V vs. SHE. This value is not concordant with reported theoretical predictions based on atomic electronegativities.
Article
The reaction of stanna- closo-dodecaborate [SnB 11H 11] (2-) (1) with CdBr 2 gave the tetrahedrally coordinated compound [Cd(SnB 11H 11) 4] (6-)(2). The same coordination mode can be found in [Hg(SnB 11H 11) 4] (6-) (3), which was obtained by reaction of stannaborate with Hg 2Cl2. Both compounds were characterized by single crystal X-ray analysis and heteronuclear NMR techniques.
  • N Vojteer
  • V Sagawe
  • J Stauffer
  • M Schroeder
  • H Hillebrecht
Vojteer N, Sagawe V, Stauffer J, Schroeder M and Hillebrecht H 2011 Chem.—A Eur. J. 17 3128–35
  • M Somer
  • K Peters
  • Von Schnering
Somer M, Peters K and von Schnering H G 1990 Crystal structure of dipotassium sodium-diphosphidoborate, K 2 NaBP 2 Z. Kristallogr. 194 133–4
  • X Feng
  • L-Y Shi
  • J-Z Hang
  • J-P Zhang
  • J-H Fang
  • Q-D Zhong
Feng X, Shi L-Y, Hang J-Z, Zhang J-P, Fang J-H and Zhong Q-D 2005 Low temperature synthesis of boron phosphide nanocrystals Mater. Lett. 59 865–7
Al 1–x B x )PSi 3 and (Al 1–x B x )AsSi 3 tetrahedral phases via reactions of Al
  • P Sims
  • T Aoki
  • R Favaro
  • P Wallace
  • A White
  • C Xu
  • J Menendez
Sims P, Aoki T, Favaro R, Wallace P, White A, Xu C, Menendez J and Kouvetakis J 2015 Crystalline (Al 1–x B x )PSi 3 and (Al 1–x B x )AsSi 3 tetrahedral phases via reactions of Al(BH 4 ) 3 and M(SiH 3 ) 3 (M = P, As) Chem. Mater. 27 3030–9
  • J Gullman
Gullman J 1990 The crystal structure of SnP J. Solid State Chem. 87 202–7
Flux growth and characteristics of cubic boron phosphide Thesis of
  • U Nwagwu
Nwagwu U 2013 Flux growth and characteristics of cubic boron phosphide Thesis of Master of Science (Manhattan: Kansas State University)
Crystal structure of cesium diphosphidoborate
  • M Somer
  • T Popp
  • K Peters
  • Von Schnering
Somer M, Popp T, Peters K and von Schnering H G 1990 Crystal structure of cesium diphosphidoborate, Cs 3 (BP) 2 Z. Kristallogr. 193 297-8