Kevin Ryan

• Professor of Chemical Nanotechnology
• University of Limerick

The advancement of lithium-ion batteries (LIBs) is vital for achieving net-zero emissions, because it enables renewable energy integration, supports electric vehicle (EV) adoption, and promotes cost-effective and sustainable solutions. The growing demand for EVs and portable electronics has amplified the need for reliable battery management systems...

Germanium (Ge) has a high theoretical specific capacity (1384 mAh g−1) and fast lithium-ion diffusivity, which makes it an attractive anode material for lithium-ion batteries (LIBs). However, large volume changes...

Here, we report the solution phase synthesis of axial heterostructure Si and Ge (hSG) nanowires (NWs). The NWs were grown in a high boiling point solvent from a low-cost Sn powder to achieve a powder form product which represents an attractive route from lab-scale to commercial application. Slurry processed anodes of the NWs were investigated in ha...

Germanium nanowire (GeNW) electrodes have shown great promise as high-power, fast-charging alternatives to silicon-based electrodes, owing to their vastly improved Li ion diffusion, electron mobility and ionic conductivity. Formation of the solid electrolyte interphase (SEI) on the anode surface is critical to electrode performance and stability bu...

Controlling the crystal phase in layered transition metal dichalcogenides (TMD) is critical for their diverse, flexible applications. However, due to the thermodynamic stability of 2H over other polymorphs, fine synthesis...

Hydrochlorothiazide is a diuretic drug and belongs to Biopharmaceutical Classification System class IV, having poor water solubility and low permeability, thus proportionally affecting its oral bioavailability and clinical efficacy. The final dosage forms play a significant role in influencing the rate and extent of absorption of class IV drugs fro...

Poor bioavailability and aqueous solubility represent a major constraint during the development of new API molecules and can influence the impact of new medicines or halt their approval to the market. Cocrystals offer a novel and competitive advantage over other conventional methods with respect towards the substantial improvement in solubility pro...

The inability of many biopharmaceutical formulations to retain their structure and integrity when in solution represents a major issue for their transport and storage, reducing their shelf-life and activity/stability. The ability to efficiently produce dried solid dosage forms of biopharmaceuticals such as proteins and nucleic acids allows for many...

The present work investigates the solubility of the stable polymorph of celecoxib (CEL) drug in a range of pure organic solvents, including methanol, isopropanol, butanol, ethyl acetate, acetonitrile and toluene, within the temperature range 278-303 K. The solid form used has been characterized by SEM, PXRD, DSC, TGA, FTIR and Raman spectroscopy. T...

Herein, we demonstrate the ability of Zn to catalyze the growth of Si nanowires via reaction temperature determined, vapour-liquid-solid (VLS) or vapour-solid-solid (VSS) growth mechanisms. This is the first reported use of a type B catalyst to grow Si nanowires via the VSS mechanism to our knowledge whereby the highly faceted Zn seeds resulted in...

Here we report the use of 1D SixGe1−x(x= 0.25, 0.5, 0.75) alloy nanowires (NWs) as anode materials for Na-ion batteries (NIBs). The strategy involves the synthesis of crystalline SixGe1−xNWsviathe solution-liquid-solid (SLS) mechanism, followed by amorphization to activate the material for Na-ion cycling within a NIB. This study demonstrates the su...

Li-ion batteries (LIBs) have become critical components in the manufacture of electric vehicles (EVs) as they offer the best all-round performance compared to competing battery chemistries. However, LIB performance at low temperature (LT) extremes of EV operation (typically −40 to 0 °C) suffers from a reduced output and diminished cycle life. LT cy...

Nanosizing of pharmaceutical drug particles is one of the most important drug delivery platforms approaches for the commercial development of poorly water-soluble drug molecules. Though nanosizing of drug particles has been proven to greatly enhance drugs dissolution rate and apparent solubility, nanosized materials have presented significant chall...

Posaconazole (PSZ) is a BCS (biopharmaceutical classification system) Class II anti-fungal drug used to treat infections in immunocompromised patients. The work presented herein describes the generation of cocrystals of PSZ with 4-aminobenzoic acid (4AMB) using supercritical CO2 as an antisolvent in GAS (Gas Antisolvent) with acetonitrile, and as a...

Copper chalcogenide nanocrystals find applications in photovoltaic inks, bio labels, and thermoelectric materials. We reveal insights in the nucleation and growth during synthesis of anisotropic Cu2ZnSnS4 nanocrystals by simultaneously performing in situ X-ray absorption spectroscopy (XAS) and small-angle X-ray scattering (SAXS). Real-time XAFS rev...

Poor solubility of new chemical entities (NCEs) is a major bottleneck in the pharmaceutical industry which typically leads to poor drug bioavailability and efficacy. Nanotechnologies offer an interesting route to improve the apparent solubility and dissolution rate of pharmaceutical drugs, and processes such as nano-spray drying and supercritical C...

Multidrug products enable more effective therapies and simpler administration regimens, provided that a stable formulation is prepared, with the desired composition. In this view, solid solutions have the advantage of combining the stability of a single crystalline phase with the potential of stoichiometry variation of a mixture. Here a drug–prodru...

Second harmonic generation and sum frequency generation (SHG and SFG) provide effective means to realize coherent light at desired frequencies when lasing is not easily achievable. They have found applications from sensing to quantum optics and are of particular interest for integrated photonics at communication wavelengths. Decreasing the footprin...

Control of polytypism in colloidal nanocrystals allows both for a shape evolution from 0D to 3D but also provides an opportunity to tailor physical properties that are crystal phase-dependent. Initiating polytypism in nanostructures is a function of multiple different control parameters that dictate nucleation and growth including reaction temperat...

Addition of electrolyte additives (ethylene or vinylene carbonate) is shown to dramatically improve the cycling stability and capacity retention (1600 mAhg-1) of Si nanowires (NWs) in a safe ionic liquid (IL) electrolyte (0.1LiTFSI-0.6PYR13FSI-0.3PYR13TFSI) . We show using post-mortem SEM and TEM, a distinct difference in morphologies of the active...

In this study, a two-dimensional population balance model with solvent removal kinetics has been developed to predict the dynamic behavior of carbamazepine form II crystals produced by a supercritical CO2 antisolvent batch crystallization process. The model was simulated and validated using experimental crystal size distribution data (CSD). The mod...

The solubility of the racemic solid phase of ketoprofen (KTP) in methanol, ethanol, isopropanol, butanol, acetonitrile, ethyl acetate, 1,4-dioxane and toluene has been determined between 273 and 303 K by a gravimetric method. FTIR and Raman spectroscopy, SEM and PXRD, have been used to characterise the solid phase. The melting data and heat capacit...

Two-dimensional (2D) layered materials are a quickly evolving area of scientific exploration, with engineering of these into further constrained dimensions and engineered architectures offering the possibility of unique physical insights. Constructing nanomaterials in dimensionally-constrained 2D network architectures is a viable way for the improv...

Supercritical CO2 antisolvent crystallization typically promotes the formation of metastable polymorphic forms of pharmaceutical drugs. However, using this technological approach in combination with the use of distinct molecular additives can provide further control over the final polymorphic form obtained. The work presented herein investigates th...

CuZnSe2 (CZSe) is an important ternary semiconductor comprised of earth-abundant elements with a suitable bandgap for visible light absorption and structural/stoichiometric versatility that make it a promising candidate for photovoltaic applications. Here we report the controlled synthesis of this compound copper chalcogenide in nanocrystal form us...

Herein, copper silicide (Cu15Si4) nanowires (NWs) grown in high densities from a metallic Cu substrate are utilized as nanostructured hosts for amorphous silicon (aSi) deposition. The conductive Cu15Si4 NW scaffolds offer an increased surface area, versus planar substrates, and enable the preparation of high capacity Li-ion anodes consisting of a n...

The ability of both bowtie and semicircle antennas to enhance waveguide input coupling efficiency in thin trench waveguides was studied for broadband applications. The waveguide outputs of trench waveguides with and without antennas were measured using a tunable laser with wavelengths ranging from 570 nm to 960 nm under both parallel and perpendicu...

Development of cost‐effective and increasingly efficient sustainable materials for energy‐storage devices, such Li‐ion batteries, is of crucial future importance. Herein, the preparation of carbon nanofibres from biopolymer blends of lignin (byproduct from the paper and pulp industry) and polylactic acid (PLA) or a thermoplastic elastomeric polyure...

Herein, the electrochemical performance of directly grown Ge nanowire anodes in full-cell Li-ion configurations (using lithium cobalt oxide cathodes) are examined. The impacts of voltage window, anode/cathode balancing and anode preconditioning are assessed. The cells had a useable upper cutoff of 3.9 V, with a higher voltage cutoff of 4.2 V shown...

Herein, textured Cu foil is presented as an attractive current collector substrate for directly grown Ge nanowire (NW) anodes. Compared to planar stainless steel (SS) current collectors, textured Cu led to an increase in achievable mass loading, removal of the requirement for a catalyst deposition step, improved adhesion of the active material and...

Poor solubility and bioavailability of new chemical entities is a major challenge that keeps plaguing the pharmaceutical industry and jeopardizes their away to the market. Nanotechnologies hold a great promise to overcome these chemical barriers. In particular, for supercritical CO2 technologies, the scientific community has seen significant develo...

Here we report the use of assemblies of SnS nanocubes as Lithium ion battery anodes. The particles are deposited in dense, conductive thin films with high gravimetric capacity using electrophoretic deposition, negating the requirement for binders or conductive additives. While SnS nanocube ensembles display both alloying and conversion modes, a sig...

The polymorphic control of the co-crystal carbamazepine-saccharin (CBZ-SAC) metastable form II was achieved by nano-droplet confinement in tandem with droplet surface charging induced by electrospraying the precursor solution. Polymorphic exclusivity...

Molecular tautomerism has been reported to play an important role in the crystallization of active pharmaceutical ingredients, particularly in the formation of pharmaceutical cocrystals and salts. In this work, by combining molecular modelling, crystallization experiments and spectroscopic techniques, we investigate possible molecular mechanisms by...

Herein, we report the synthesis and complete structural characterization of curved CuIn¬1-xGax(S1-ySey)2 (x = y = 0.5) nanocrystals, which adopt a 2D nanoplate morphology and crystallize in the hexagonal wurtzite phase. A detailed transmission electron microscopy (TEM) analysis reveals that the 2D nanoplates are predominately [001]-oriented and exh...

Calcium carbonate and carbonate-hydroxyapatite are known to form inorganic components of crystals and calcareous concretions found in many non-skeletal tissues and structures including the pineal gland. We used advanced surface analyses techniques such as polarization microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), microfocu...

Herein, we report a novel approach to form axial heterostructure nanowires composed of linearly distinct Ni silicide (Ni2Si) and Si segments via a one-pot solution synthesis method. Initially, Si nanowires are grown using Au seeds deposited on a Ni substrate with the Si delivery in the solution phase using a liquid phenylsilane precursor. Ni silici...

Here we report an interesting observation on anode materials for lithium ion batteries that undergo combined conversion and alloying lithiation processes during cycling (CAMs). These materials are generating interest as low cost and high capacity alternatives to graphite. We find that common testing protocols (CTPs) are unsuitable for assessment of...

Here, we report the synthesis of a bimetallic 2D interpenetrated metal‐organic material (MOM) and its use as a sacrificial precursor for the formation of a Cu2SnS3/SnS2/C composite. The one‐step sulfurisation of the novel Sn/Cu‐MOM represents a facile method for the preparation of an effective anode material for Li‐ion battery applications. The Cu2...

Highly aligned Copper Zinc Tin Sulfide (CZTS) nanorods (NRs) electrophoretically deposited directly on the current collector are tested for suitability as Li-ion battery (LIB) anodes in both half cell (HC) and full cell (FC) configurations. This facile fabrication process offers several advantages for high-performance nanostructured battery electro...

Here, we report the application of axially heterostructured nanowires consisting of alternating segments of silicon and germanium, with a tin seed, as lithium-ion battery anodes. During repeated lithiation and delithiation, the heterostructures completely rearrange into a porous network of homogenously alloyed Si1-xGex ligaments. The transformation...

The optimum geometry for waveguide propagation was determined by comparing bowtie and semicircle antenna cuts to a standard plain waveguide with a 635 nm laser. The results of both experimental data and COMSOL simulations proved that the bowtie antenna increased waveguide output in comparison to the plain waveguide with the semicircle pattern showi...

Herein, we report the formation of silicon, germanium and more complex Si-SixGe1-x and Si-Ge axial 1D heterostructures, at low temperatures in solution. These nanorods/nanowires are grown using phenylated compounds of silicon and germanium as reagents, with precursor decomposition achieved at substantially reduced temperatures (200 °C -for single c...

Li‐ion batteries containing cost‐effective, environmentally benign cathode materials with high specific capacities are in critical demand to deliver the energy density requirements of electric vehicles and next‐generation electronic devices. Here, the phase‐controlled synthesis of copper sulfide (CuxS) composites by the temperature‐controlled sulfu...

Here we report the first detailed investigation into the selenization mechanism of thin films of wurtzite copper zinc tin sulfide (CZTS) nanorods (NRs), giving particular emphasis to the role of the long-chain organic ligands sur-rounding each NR. During selenization, the NRs undergo a selenium-mediated phase change from wurtzite to kesterite, conc...

Here we report the formation of high capacity Li-ion battery anodes from Si1-xGex alloy nanowire arrays that are grown directly on stainless steel current collectors, in a single step synthesis. The direct formation of these Si1-xGex nanowires (ranging from Si0.20Ge0.80 to Si0.67Ge0.33) represents a simple and efficient processing route for the pro...

Here we report new insights into the effect various electrolyte additives have on the cycling stability and rate capability of Si nanowire (NW) Li-ion battery anodes. The additives tested were vinylene carbonate, vinyl ethylene carbonate, fluoroethylene carbonate and lithium bis(oxalato)borate. All four significantly improve the capacity retention...

Controlling pharmaceutical polymorphism in crystallization processes represents a major challenge in pharmaceutical science and engineering. For instance, CO2-antisolvent crystallization typically favors the formation of metastable forms of carbamazepine (CBZ), a highly polymorphic drug, with impurities of other forms. This work demonstrates for th...

Herein, we report the high density growth of lead seeded germanium nanowires (NWs) and their development into branched nanowire networks suitable for application as lithium ion battery anodes. The synthesis of the nanowires from lead seeds occurs simultaneously in both the liquid zone (SLS growth) and solvent rich vapor zone (VLS growth) of a high...

The electrochemical behavior of binder-free, germanium and silicon nanowires as high capacity anode materials for lithium-ion battery systems are investigated in an ionic liquid electrolyte. Cyclic voltammetry, cycling tests and impedance spectroscopy reveal a highly reversible lithium alloying / de-alloying process, as well as promising compatibil...

This work reported an improved approach to the synthesis of iron oxide nanostructures using iron(III) chloride as the precursor and hexamethylenetetramine (HMTA) as the key auxiliary. A range of iron oxide (alkoxide) nanostructures including nanosheets, hierarchical flowers (assembled by thin nanosheets), mesoporous hollow nanospheres and solid nan...

We report the formation of NiGe nanowires by the thermal decomposition of diphenylgermane, in the presence of a bulk Ni foil, in a solvent vapor growth system. The reaction occurs by the initial formation of a NiGe layer on the foil which progresses to the growth of nanowire occlusions of the same phase, typically 40 nm in diameter. Switching the s...

This review captures the synthesis, assembly, properties, and applications of copper chalcogenide NCs, which have achieved significant research interest in the last decade due to their compositional and structural versatility. The outstanding functional properties of these materials stems from the relationship between their band structure and defec...

Herein we report the formation of multi-layered arrays of vertically aligned and close packed semiconductor nanorods in perfect registry at a substrate using electric field assisted assembly. The collective properties of these CdSexS1-x nanorod emitters are harnessed by demonstrating a relatively low amplified spontaneous emission (ASE) threshold a...

Here we report the two-stage assembly of semiconductor nanorods at substrates. The nanorods preassemble into 2D discs by self-organisation and these discs are deposited into conformal layers at substrates using electric field assembly. The intermediate self-assembly step can be eliminated by carrying out a judicious ligand exchange allowing selecti...

Epoxy resin (ER) thermosetting adhesives provide highly cross-linked 3-dimensional structures leading to highly stable and strong mechanical/physical performance in a wide range of bonding applications. However, such excellent physical attributes pose a significant challenge with respect to disassembly of the bonded adherends and previous disassemb...

A wide range of physical properties from opto-electronic (e.g. band gap) to structural (e.g. hardness) can be affected without changing the composition of the solid but just by altering the crystal phase. Here, we report selective structural phase transition of metastable wurtzite CZTSSe nanocrystals into more stable phases such as zinc-blende and...

Cu2SnSe3 (CTSe) has attracted a great deal of interest in a large range of technoligical applications due to its unique optical and electrical properties. The synthesis of CTSe in nanocrystal form is particularly interesting with a range of different crystal structures attainable. We review recent progess in the colloidal synthesis of CTSe nanocrys...

Li-alloying materials such as Si and Ge nanowires have emerged as the forerunners to replace the current, relatively low-capacity carbonaceous based Li-ion anodes. Since the initial report of binder-free nanowire electrodes, a vast body of research has been carried out in which the performance and cycle life has significantly progressed. The study...

Herein, we report the formation of multi-segment Si-Ge axial heterostructure nanowires in a wet chemical synthetic approach. These nanowires are grown by the liquid injection of the respective silicon and germanium precursors into the vapour phase of an organic solvent in which a tin-coated stainless steel substrate is placed. The Si-Ge transition...

A method has been developed for the wet solution synthesis of core shell heterogeneous nanowires. An ultrathin silica layer was first grown around plain silver nanowires to act as a suitable insulator. An outer nanoparticle layer was then attached through heteroaggregation by dispersing the un-functionalized nanowires in toluene solutions containin...

Cu2SnS3 (CTS) nanorods were synthesized with a controllable aspect ratio via a facile phosphine-free colloidal synthesis. This synthesis can be readily extended to obtain Cu2ZnSnS4 (CZTS) nanorods with tunable Zn content.

This Perspective will look at the occurrence of polytypism in colloidal nanocrystals of metal chalcogenides. The low energy barrier between growth in wurtzite and zincblende crystal phases allows the occurrence of both in a single particle which has a dramatic influence on shape control. To date, various strategies have been employed to understand...

Electrophoretic deposition is used to deposit CdS and CdSe nanorods onto planar centimetre scale substrates directly from solution. It is found that the net charge and dipole interactions on the nanorods are the sole factors in the resulting assemblies formed upon deposition, with the higher net charge nanorods forming vertically aligned assemblies...

Here we report the rational design of a high-capacity Li-ion anode material comprising of Ge nanowires with Si branches. The unique structure provides an electrode material with tunable properties, allowing the performance to be tailored for either high capacity or high rate capability by controlling the mass ratio of Si to Ge. The binder free Si-G...

We report the formation of silicon, germanium and alloyed Si1-xGex nanowires by direct pyrolysis of liquid precursors on a heated substrate in an inert environment. The nanowires form in high density on the substrate with a fast reaction time. We use SEM, HRTEM, EDX-STEM, and Raman spectroscopy to carry out an in depth study into the population dis...

Herein, we report shape control in the CZTSSe nanocrystal system by tuning the occurrence of polytypism between wurtzite and zinc-blende phases. We have isolated the key control factors in this system and show that the choice of solvents/surfactants and precursors and how they are introduced can allow shape control from dots to ellipsoids to arrows...

This article describes a complete study of the evolution of composition (from binary to quaternary) and shape (0D-1D) during the synthesis of CZTS nanocrystals. Aliquot studies were used to track the nucleation and growth in the early stages. Distinctive stages are evident in the reaction due to the progressive incorporation of tin and zinc into th...

This article describes a complete study of the evolution of composition (from binary to quaternary) and shape (0D–1D) during the synthesis of CZTS nanocrystals. Aliquot studies were used to track the nucleation and growth in the early stages. Distinctive stages are evident in the reaction due to the progressive incorporation of tin and zinc into th...

Amorphous, low porosity carbon spheres of the order of a few microns in size were prepared by carbonization of squalane (C30H62) in supercritical CO2 at 823 K. The spheres were characterized and used as catalysts' supports for Pd. Near edge X-ray absorption fine structure studies of the spheres revealed sp2 and sp3 hybridized carbon. To activate ca...

Here we describe a relatively facile synthetic protocol for the formation of Si-Ge and Si-Ge-Si1-xGex axial nanowire heterostructures. The wires are grown directly on substrates with an evaporated catalytic layer placed in the vapour zone of a high boiling point solvent with the silicon and germanium precursors injected as liquids sequentially. We...

We report a low-energy colloidal synthesis route to homogeneously alloyed Cu−In−Zn−S nanorods that have the wurtzite crystal structure and demonstrate that the optical band gap of these nanorods is compositionally tunable through direct control of the zinc precursor molar ratio. The as-synthesized nanorods are highly monodisperse and can be assembl...

GREENLION is a Large Scale Collaborative Project within the FP7 (GC.NMP.2011-1) leading to the manufacturing of greener and cheaper Li-Ion batteries for electric vehicle applications via the use of water soluble, fluorine-free, high thermally stable binders, which would eliminate the use of VOCs and reduce the cell assembly cost. The project has 6...

A rapid (< 30 s) synthetic protocol for the formation of high performance Ge nanowire based Li-ion battery anodes is reported. The nanowires are formed in high density by the liquid deposition of a Ge precursor without solvents directly onto a heated stainless steel substrate under inert conditions. The novel growth system exploits the in-situ form...

In this article we outline the assembly of binary, ternary and quaternary nanorods using three separate protocols. The rods are the important photoabsorbers CdS, CdSexS1−x, CuInxGa1−xS, and Cu2ZnSnS4. In the droplet based assembly, we form either 1D rail-tracks or 2D discs of aligned rods depending on the net charge. In the vial based approach, we...

Group IV Nanowires have strong potential for several biomedical applications. However, to date their use remains limited because many are synthesised using heavy metal seeds and functionalised using organic ligands to make the materials water dispersible. This can result in unpredicted toxic side effects for mammalian cells cultured on the wires. H...

Here we report an investigation of systematic control of crystal phase in the ternary nanocrystal system, dicopper tin triselenide. Optimizing the synthetic parameters allows modulation between nucleation and growth in either the hexagonal or cubic phase. In addition to size controlled single crystals, the particles can be tuned to occur as 1D line...

In polycrystalline semiconductors, grain boundaries are often sites with prevalence for electron-hole recombination and various strategies have been followed to minimize grain boundary areas. Generally, large grains or epitaxial films can be obtained at high temperatures. However, high growth temperatures limit the choice of substrate materials and...

Here we report the formation of high-performance and high-capacity lithium-ion battery anodes from high density germanium nanowire arrays grown directly from the current collector. The anodes retain capacities of ∼ 900 mAh/g after 1100 cycles with excellent rate performance characteristics, even at very high discharge rates of 20-100C. We show by a...

Wurtzite-type Cu2ZnSn(S1-xSex)4 (x = 0—1) nanocrystals are synthesized from mixtures of Cu(acac)2, Zn(OAc)2, Sn(OAc)4, dodecanethiol, diphenyl diselenide, trioctylphosphine oxide, and octadecene (Ar flow, 155 °C, 15 min).

Homogenously alloyed CdSexS1-x nanorods with controlled aspect ratios are synthesised by a hot-injection colloidal route. The optical absorption and photoluminescence emission are compositionally tunable with chalcogen ratios. The synthetic protocol is sufficiently robust to allow good control of rod aspect ratios, with low polydispersities, suited...

Si and Ge nanowires have attracted widespread interest due to their suitability for photovoltaic, nanoelectronic, sensing and energy storage applications. As a result, a variety of synthetic protocols have emerged which include chemical vapour deposition and solution phase approaches. Early solution based approaches were hindered by the high nuclea...

Anorganische Nanostrukturen: Legierte 10 nm große Cu2ZnSn(S1−x Sex )4‐Wurtzitnanokristalle (mit variabler Zusammensetzung x=0–1) wurden durch Heißinjektion synthetisiert. Photolumineszenz(PL)‐Spektren der Kristalle zeigen eine Bandlücke zwischen 0.9–1.4 eV, die über die Zusammensetzung der Nanokristalle gesteuert werden kann und direkt mit dem Verh...

Tin oxide (SnO2) is considered a very promising material as a high capacity Li-ion battery anode. Its adoption depends on a solid understanding of factors that affect electrochemical behavior and performance such as size and composition. We demonstrate here, that defined dispersions and structures can improve our understanding of Li-ion battery ano...

Ligand-capped nanoparticles are dispersed in an organic solvent. There is then phase transfer of the nanoparticles introducing into the organic solvent an aqueous solution of polymer surfactant dissolved in water. The organic solvent and the aqueous solution are then mixed until the polymer forms micelles which encapsulate the nanoparticles in asse...

Super crystallization of ligand-capped nanocrystals into defined periodic solids from solution is the definitive demonstration of their self-organizing properties. To date, this has been mainly limited to spherical nanocrystals where organization emulates atom or molecule packing in regular crystals with the most thermodynamically stable arrangemen...

Inorganic nanostructures: Alloyed Cu2 ZnSn(S1-x Sex )4 wurtzite nanocrystals (10 nm in size) with a varying composition (x=0-1) were synthesized using a colloidal hot injection route. A photoluminescence (PL) emission study of these nanocrystals shows a compositionally tunable band-gap ranging between 0.9-1.4 eV that directly correlates to the sulf...

Silicon and germanium nanowires are grown in high density directly from a tin layer evaporated on stainless steel. The nanowires are formed in low cost glassware apparatus using the vapor phase of a high boiling point organic solvent as the growth medium. HRTEM, DFSTEM, EELS, and EDX analysis show the NWs are single crystalline with predominant 111...

Tin oxide (SnO2) is considered a very promising material as a high capacity Li-ion battery anode. Typically, the electrochemical performance of tin oxide based anodes is dependent on various factors such as their size and composition. Here, we demonstrate how defined dispersion of nanostructures can improve the understanding of the relationship bet...

The formation of Cu2SnSe3 tetrapod nanocrystals is reported using a hot injection colloidal synthesis. The ternary copper chalcogenide nanocrystals nucleate with a cubic core with four short wurzite arms.

Unique bimodal distributions of single crystal epitaxially grown In2O3 nanodots on silicon are shown to have excellent IR transparency greater than 87% at 4 µm without sacrificing transparency in the visible region. These broadband antireflective nanodot dispersions are grown using a two-step metal deposition and oxidation by molecular beam epitaxy...

The growth of Si/Ge axial heterostructure nanowires in high yield using a versatile wet chemical approach is reported. Heterostructure growth is achieved using the vapor zone of a high boiling point solvent as a reaction medium with an evaporated tin layer as the catalyst. The low solubility of Si and Ge within the Sn catalyst allows the formation...