Wanjun Yan

• Anshun University

Herein, the electronic structure and optical properties of GaAs doped with rare-earth elements (Sc, Y, La, Ce, and Pr) were evaluated using the first-principles method. Results showed that the lattice constants and cell volume of GaAs increased after doping. Band structure calculations indicated that the lowest conduction band and highest valence b...

Gallium nitride (GaN) with layered heterostructure of Wurtzite/Zinc-blende (WZ/ZB) has many excellent properties, but the thickness of the layered heterostructures and nano-grinding methods immensely affect the performance of the material. This study employs molecular dynamics (MD) simulation to examine the impact of rotation-assisted grinding on G...

Context: Silicon carbide nanowires (SiCNWs) are considered a promising alternative material for application in lithium-ion batteries, with researchers striving to develop new electrode materials that exhibit high capacity and high charge/discharge rate performance. To gain a deeper understanding of the application of SiCNWs in semiconductor materi...

The shape of ceramic particles is one of the factors affecting the properties of metal matrix composites. Exploring the mechanism of ceramic particles affecting the cooling mechanical behavior and microstructure of composites provides a simulation basis for the design of high-performance composites. In this study, molecular dynamics methods are use...

Silicon carbide (SiC) plays a vital role in devices used in several fields, such as communications, displays, and lighting. The quality of SiC growth is critical to the fabrication of high-performance SiC devices; thus, it is important to explore its growth mechanism. Herein, we used approaches based on molecular dynamics to simulate the induced cr...

Investigation of the dislocation and structural evolution associated with the study of the deformation behavior of composites is extremely vital among the scientific community. This study examines the mechanical behavior of idealized Cu/SiC composites using molecular dynamics simulations. The mechanical properties were tested by stretching the comp...

A superior piezoelectric coefcient and diminutive lattice thermal conductivity are advantageous for the application of a two-dimensional semiconductor in piezoelectric and thermoelectric devices, whereas an imperfect piezoelectric coefcient and large...

This study evaluated the electronic structure and optical properties of Fe-doped, Ni-doped, and (Fe,Ni)-co-doped Cu2ZnSnS4 through the first-principles pseudopotential plane-wave method based on density functional theory. The results indicated that Fe single-doping and Ni single-doping Cu2ZnSnS4 can reduce the charge transfer number of adjacent S a...

In this paper, the electronic band structure, Rashba effect, hexagonal warping, and piezoelectricity of Janus group-VIA binary monolayers STe2, SeTe2, and Se2Te are investigated based on density functional theory (DFT). Due to the inversion asymmetry and spin-orbit coupling (SOC), the STe2, SeTe2 and Se2Te monolayers exhibit large intrinsic Rashba...

By using the pseudopotential plane-wave method of first principles based on density functional theory, the band structure, density of states and optical properties of Cu2ZnSnS4 under isotropic stress are calculated and analyzed. The results show that Cu2ZnSnS4 is a direct band gap semiconductor under isotropic stress, the lattice is tetragonal, and...

Self-powered photodetectors have huge potential applications in wearable electronics, extreme environments and military fields. In this work, two types of van der Waals Cs-I-BP and Sn-I-BP heterostructures have been studied fully through first-principles calculations. The results demonstrate that both Cs-I-BP and Sn-I-BP heterostructures have type-...

The effect of two-dimensional borophene on the adsorption properties of gas molecules was studied by first-principles method. The adsorption energies of gas molecule on the four adsorbed site were first computed. Through compare these adsorption energies of different adsorbed site, the most stable of adsorption configuration were determined. In ord...

Ammonium tungstate precursor system are one of promising preparation routes for sol-gel tungsten oxide (WO3) film because of its low-cost preparation, good solution stability, and good solvent compatibility. Nevertheless, we notice that an incomplete ion extraction (called electrochromic sticking image) behavior of electrochromic WO3 film prepared...

The microstructure evolution of liquid silicon carbide (SiC) during rapid solidification under different pressure values is simulated with the Tersoff potential using molecular dynamics. The structure evolution characteristics of SiC are analyzed by considering the pair distribution function, bond angle distribution, coordination number, and the di...

Designing compound photocatalyst with heterostructure is generally supposed to be a pragmatic strategy to attain effective charge separation and improve solar-driven water splitting. In this work, the photogenerated carrier transfer and photocatalytic properties of TiO2/h-BN heterostructure are systematically explored by density functional theory (...

A first-principles study was performed to investigate the adsorption properties of gas molecules (CO, CO2, NO, and NO2) on carbon- (C-), nitrogen- (N-), and oxygen-doped (O) borophene. The adsorption energies, adsorption configurations, Mulliken charge population, surface work functions, and density of states (DOS) of the most stable doped borophen...

Extension of the light absorption range and a reduction of the possibility of the photo-generated electron-hole pair recombination are the main tasks to break the bottleneck of the photocatalytic application of TiO2. In this paper, we systematically investigate the electronic and optical properties of Sc-doped, C-doped, and Sc/C-codoped TiO2 (101)...

Borophene is a new type of two-dimensional material with a series of unique and diversified properties. However, most of the research is still in its infancy and has not been studied in depth. Especially in the field of semiconductor optoelectronics, there is no related research on the modulation of photoelectric properties of borophene. In this wo...

First-principles spin-polarized density functional theory (DFT) is employed to investigate the effect of two nearest V substitution doping on magnetism of two dimension (2D) monolayer CrSi 2. Calculation of formation energy confirms that all V-doped monolayer CrSi 2 are thermodynamically stable. A total density of states, near Fermi level, are deri...

Multicrystalline silicon was grown by directional solidification method, and different growth rates was obtained by optimizing the growth process. The influence of the growth rate on the minority carrier lifetime of the multicrystalline silicon ingot was studied. The results show that the infrared image of the middle and lower part of the silicon b...

Using multicrystalline silicon miscellaneous materials for ingot casting, optimizing the ingot casting process and charging formula, the utilization rate of silicon material is 66.15%, effectively improving the utilization of multicrystalline silicon miscellaneous materials. The minority carrier lifetime of the silicon block is 5.02us, which meets...

The high-quality growth of semiconducting single crystals is the basis of the fabrication of high-performance devices. SiC is a promising semiconductor material for fabricating power electronics and radio frequency devices that require crystals to exhibit less crystal defects and high crystal density. In this study, the crystallization induced by t...

This paper describes a new approach to regulate the photoelectric properties of two-dimensional SiC materials. The first-principles pseudo-potential plane wave method is used to calculate the geometric structure, electronic structure and optical properties of two-dimensional (2D) SiC co-doped by the adjacent elements of C-Si (such as B and N). The...

We calculated the electronic structure, magnetism and optical properties of the Sc-doped, Y-doped, and (Sc, Y)-codoped anatase TiO2 (101) surface using a projector augmented wave (PAW) method with GGA + U approximation. Sixteen doping systems were considered in the present work. The lattice distortion results in the generation of an internal local...

First-principle calculations based on spin-polarized density functional theory were performed to investigate the effect of Fe and Ti substitution doping on magnetic property of monolayer CrSi2. The electronic structures, binding energy, magnetic property, total and partial density of states, and spin density of monolayer CrSi2 are scientifically st...

The electronic structures, formation energy and optical properties of Cu-doped, C-doped, and (Cu, C)-codoped TiO 2 were investigated by the projector augmented wave (PAW)method within GGA + U approximation. The results show that the lattice distortion of the [email protected]&[email protected] system is the largest in all doping systems. The optica...

The effects of doping on the electronic and magnetic properties of the quaternary Heusler alloy TiZrCoIn were investigated by first-principles calculations. Results showed that the appearance of half-metallicity and negative formation energies are associated in all of the TiZrCoIn1−xGex compounds, indicating that Ge doping at Z-site increases the s...

We investigated the electronic and magnetic properties of bulk and monolayer CrSi2 using first-principle methods based on spin-polarized density functional theory. The phonon dispersion, electronic structures, and magnetism of bulk and monolayer CrSi2 were scientifically studied. Calculated phonon dispersion curves indicated that both bulk and mono...

We investigate magnetism and optical properties of intrinsic and Mn-doped monolayer CrSi2 using the first-principle methods based on density functional theory. The results show that both monolayer CrSi2 sheets are metallic and ferromagnetic (FM) that hold promise in future 2D magnetic devices. In spite the slight reduction of the total magnetic mom...

A first-principle method is used to calculate the geometric structure, energy band structure, electronic state density, and optical properties of C-doped Ca2Si. Results show that volume of Ca2Si decreases, and band gap increases after doping with C. The optical properties of Ca2Si after C doping change as follows: ε1(0) and refractivity index incre...

Molecular dynamics simulations with Tersoff-Ziegler-Biersack-Littmark (Tersoff-ZBL) potential and adaptive intermolecular reactive empirical bond order (AIREBO) potential are performed to study the substitutional process of silicon ions by bombardment. The silicon ions bombardment of graphene is simulated at energies 100 eV, 100 eV, 68 eV and 67 eV...

Molecular dynamics simulations with adaptive intermolecular reactive empirical bond order (AIREBO) potential are performed to investigate the effects of rectangular nanoholes with different areas, aspect ratios (length/width ratios) and orientations on the tensile strength of defective graphene. The simulations reveal that variation of area, aspect...

This study uses the first-principle pseudo-potential method based on density functional theory to investigate the structure stability, geometrical structure, electronic structure, deformation charge density, atomic orbital and bond population, and optical properties of graphene-like structures SixC1−x (x = 0.02, 0.08, 0.2, 0.4, 0.5). Geometrical st...

Understanding the structural evolution of covalent systems under rapid cooling is very important to establish a comprehensive solidification theory. Herein, we conducted molecular dynamics simulations to investigate the crystallization of silicon-germanium (SiGe) alloys. It was found that during crystallization, the saturation and orientation of co...

The electronic structure and optical properties of V-doped CrSi2 have been calculated by using the first-principle peudo-potential plane-wave method based on the density functional theory.The parameters and properties of structure were given and the theory data were offered to research the effect of V doping into CrSi2. The calculations of energy b...

By using the first principle pseudo-potential plane-wave method, the geometrical structure, electronic structure and optical properties of β-FeSi2 with doping rare earth (Y, Ce) are calculated and analyzed. The calculated results of the geometrical structure show that the lattice constants change, the volume of lattice reduces. Electronic structure...

By using the first principle pseudo-potential plane-wave method based on the density function theory (DFT), the geometrical structure, electronic structure and optical properties of β-FeSi2 with doping Ac are calculated and analyzed. The calculated results of the geometrical structure show that the lattice constants a, b and c change, the volume of...

Based on the first principles pseudo-potential plane-wave method, geometrical structure, electronic structure, and optical properties of V-Al co-doped CrSi2 are calculated. The photoelectric properties of un-doped CrSi2, and co-doped with V and Al, and single-doped with V or Al are compared in detail. The results show that: co-doped with V and Al,...

Molecular dynamics simulations with Tersoff–Ziegler–Biersack–Littmark (Tersoff–ZBL) potential and adaptive intermolecular reactive empirical bond order (AIREBO) potential are performed to study the effect of irradiated graphene with silicon ion at several positions and energy levels of 0.1–1000 eV. The simulations reveal four processes: absorption,...

Quenching process of liquid silicon carbide (SiC) is simulated with Tersoff potential by using molecular dynamic. Structural characteristics of SiC are analyzed by radial distribution function, angular distribution function, coordination number, and Voronoi polyhedron index. Results show that both heteronuclear and homonuclear bonds exist and no at...

Based on the density functional theory (DFT), the plane-wave pseudo-potential method was used to calculate structural stabilities, electronic structures, and ferromagnetism of Fe3Si and Fe12Si3C compounds. The stability of the solid solution alloy increases with the addition of C, which occupying the Si site. Calculating the density of the states a...

Microstructural evolution of SiC during melting process is simulated with Tersoff potential by using molecular dynamics. Microstructural characteristics are analyzed by radial distribution function, angle distribution function and Voronoi polyhedron index. The results show that the melting point of SiC with Tersoff potential is 3249 K. Tersoff pote...

Elastic constants, ferromagnetism and electronic structures of Fe11MoSi4, Fe11TiSi4, and Fe11NbSi4 are studied by first-principles calculations with density functional theory (DFT). It is found that the ductility of Fe3Si could be obviously improved with the addition of Ti. The G/B-0 of Fe11TiSi4 is 0.483, which means that it is ductile. The strong...

In this paper, structural evolutions of germanium cluster are studied by molecular dynamics simulations during quenching processes. Three-dimensional atomic configurations of germanium cluster are established. Our simulation results are in good agreement with the experimental ones. The structural properties of germanium are described in detail by m...

The rapid solidification of liquid silicon carbide (SiC) is studied by molecular dynamic simulation using the Tersoff potential. The structural properties of liquid and amorphous SiC are analyzed by the radial distribution function, angular distribution function, coordination number, and visualization technology. Results show that both heteronuclea...

By using the pseudo-potential plane-wave method of first principles based on the density function theory, the geometrical, electronic structures and optical properties of FeSi1.875M0.125 (M = B, N, Al, P) were calculated and analyzed. The calculated structural parameters depend strongly on the kinds of dopants and sites. The total energy calculatio...

The melting kinetics of bulk SiC is studied by using classical molecular dynamics simulation. The mean square displacement, diffusion coefficient, Lindemann index and non-Gaussian parameter are used to analyze the melt nucleation and macrokinetics in the melting process. Melting occurs when the superheated crystal spontaneously generates many Linde...

A detailed theoretical study on the band structure, electronic density and optical properties of β-FeSi2 under the isotropic stress is performed based on the first-principles pseudopotential method. The results show that the lattice constants of β-FeSi2 change with different stress. With the compression stress increasing, the densities of Fe-d and...

The solidification processes of liquid Si are studied by molecular dynamics simulation using the Stillinger–Weber potential. The structural properties of liquid and amorphous silicon are analyzed by means of several structural analysis methods. Amorphous silicon network is formed during the solidification processes of liquid Si. The simulation resu...

The electronic structures and magnetism of Fe3Si intermetallic compounds have been investigated by using first principle methods based on plane-wave pseudo-potential theory. The calculated cohesive energy and heat of formation indicated that Fe3Si intermetallic compounds have the strong alloying ability and high structural stability. The calculatio...

By using pseudo-potential plane-wave method of the first principle based on the density function theory, geometrical structure, electronic structure and optical properties of Al-doped CrSi 2 are calculated and analyzed. The calculated results on geometrical structure and electronic structure show that the lattice constant a and b increase while c h...

The β-FeSi2 thin film has been applied in the research field of the solar cell, and the thickness of β-FeSi2 absorption layer was chosen through the experiments. However, Up to now neither the optimal thickness of β-FeSi2 absorption layer nor the relationship between the thickness of β-FeSi2 absorption layer and the solar photo wavelength has been...

The geometrical structure and electronic structure of CrSi 2 with doping V were investigated by using first principle based on the plane wave pseudo-potential theory. The calculation of band structure result shows that the band gap decreased from 0.35eV (pure CrSi2) to 0.25eV (V doped). The valence band and conduction band near the Fermi energy is...

By using the first principle pseudo-potential plane-wave method based on the density function theory, geometrical structure, electronic structure and optical properties of Co-doped β-FeSi2 are calculated and analyzed. The calculated results of the geometrical structure and electronic structure show that the lattice constant a increases while b and...

Combined with the solar spectrum, the photon absorption coefficient of the β-FeSi2 thin film has been analyzed, and then the thickness of the absorption layer of β-FeSi2 thin film solar cell has been analyzed and theoretically calculated. The results show that, under the condition of the β-FeSi2 thin film with high quality, when the optical absorpt...

The electronic structure and optical properties of Fe1-xMnxSi2 have been studied using the first principle plane-wave pseudo-potential based on the density function theory. Substitutional doping is considered with Mn concentrations of x=0.0625, 0.125, 0.1875 and 0.25, respectively. The calculated results show that the volume of β-FeSi2 increase and...

The electronic structure and optical properties of Mg2Si for the epitaxial relationship Mg2Si (111)//Si (111) are calculated by using the first-principles pseudopotential method based on the density functional theory. The results show that Mg2Si is the most steady state when the lattice parameter a of the primitive cell is 0.4522 nm; Mg2Si is an in...

The electronic structure and optical properties of Fe(1-x)Co(x)Si(2) have been studied using the first principle plane-wave pseudo-potential based on the density function theory. Substitutional doping is considered with Co concentrations of x=0.0625, 0.125, 0.1875 and 0.25, respectively. The calculated results show that the volume of beta-FeSi(2) i...

The electronic structure and optical properties of Mn-doped CrSi2 have been calculated using the first-principles pseudo-potential method based on density functional theory. The calculated results show that CrSi2 is an indirect semiconductor and the indirect band gap is 0.35 eV, the Fermi level enters conduction band and the band gap narrows after...

Using the first principle methods based on the plane-wave pseudo-potential theory, band structure, density of states and optical properties of CrSi2 were studied. The calculation of band structure shows that CrSi2 is an indirect semiconductor whose band gap is 0.353 eV. Density of states is mainly composed of 3d electron of Cr and 3p electron of Si...

The electronic structure of stressed CrSi2 was calculated using the first-principle methods based on plane-wave pseudo-potential theory. The calculated results showed that, under the uniaxial compression, the energy level of CrSi2 shifted toward high energy and its energy gap became wider with the increasing uniaxial stress, while the gap became na...

The electronic structure and optical properties of impurity (Mn, Cr, Co, Ni)-doped β-FeSi2 have been studied using the first principle plane-wave pseudo-potential based on the density function theory. The calculated results show that Mn prefers the FeI site, whereas Cr, Co, and Ni prefer the FeII site. The change about the volume and the atom posit...

The geometric parameters and the electric and optical properties of β-FeSi2 are calculated using first principle methods based on plane-wave pseudo-potential theory in detail. The results indicate that: (1) β-FeSi2 is a quasi-direct semiconductor and the band gap is 0.74eV. The density of states is mainly composed of Fe 3d and Si 3p. (2) The valenc...