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Results for “INDIUM COMPOUNDS”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Material design of indium-based compounds: Possible candidates for charge, valence, and bond disproportionation and superconductivity

Here, we design and investigate the physical properties of new indium compounds A In X 3 ( A = alkali metals, X = F or Cl). We find nine new In-based materials in their ground state that are thermodynamically stable but are not reported in ICSD (Inorganic Crystal Structure Database). We also discuss several metastable structures. This new series of materials display multiple valences, charge and bond disproportionation, and dimerization. The most common valence of In is 3+. We also find two rare alternatives, one has In 2+ with In-In dimerization and the other shows valence disproportionation to In 1+ and In 3+ with bond disproportionation. We study the possibility of superconductivity in these new In compounds and find that CsInF 3 has a transition temperature about 24 K with sufficient hole doping and pressure.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Regularly arranged indium islands on glass/molybdenum substrates upon femtosecond laser and physical vapor deposition processing

A bottom-up approach is presented for the production of arrays of indium islands on a molybdenum layer on glass, which can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide used in photovoltaics. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2017

Comparison of the toxicity of sintered and unsintered indium-tin oxide particles in murine macrophage and epidermal cells

Indium-tin oxide (ITO) is used to produce flat panel displays and several other technology products. Composed of 90% indium oxide (In{sub 2}O{sub 3}) and 10% tin oxide (SnO{sub 2}) by weight, ITO is synthesized under conditions of high heat via a process known as sintering. Indium lung disease, a recently recognized occupational illness, is characterized by pulmonary alveolar proteinosis, fibrosis, and emphysema. Murine macrophage (RAW 264.7) and epidermal (JB6) cells stably transfected with AP-1 to study tumor promoting potential, were used to differentiate between the toxicological profiles of sintered ITO (SITO) and unsintered mixture (UITO). We hypothesized that sintering would play a key role in free radical generation and cytotoxicity. Exposure of cells to both UITO and SITO caused a time and dose dependent decrease of the viability of cells. Intracellular ROS generation was inversely related to the dose of both UITO and SITO, a direct reflection of the decreased number of viable RAW 264.7 and JB6/AP-1 cells observed at higher concentrations. Electron spin resonance showed significantly increased hydroxyl radical (·OH) generation in cells exposed to UITO compared to SITO. This is different from LDH release, which showed that SITO caused significantly increased damage to the cell membrane compared to UITO. Lastly, the JB6/AP-1 cell line did not show activation of the AP-1 pathway. Our results highlight both the differences in the mechanisms of cytotoxicity and the consistent adverse effects associated with UITO and SITO exposure. - Highlights: • Sintered indium-tin oxide significantly impacts cellular viability and LDH release. • Unsintered indium-tin oxide impacts free radical production and DNA damage. • Indium compounds do not activate the AP-1 pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Lateral carrier confinement in InGaN quantum-well nanorods

We review our studies on lateral carrier diffusion in micro-fabricated samples of InGaN nanorods and their parent quantum wells. The carrier diffusion is observed to be strongly confined in nanorods, as manifested by the reduction in the delayed-rise component of time-resolved photoluminescence traces. We further argue that the confinement of carrier diffusion can be applied to suppress the efficiency droop related to defect state recombination and to assist in the energy transfer between InGaN nanorods and nanocrystal phosphors for color conversion.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

Investigating the electronic properties of Al{sub 2}O{sub 3}/Cu(In,Ga)Se{sub 2} interface

Atomic layer deposited (ALD) Al{sub 2}O{sub 3} films on Cu(In,Ga)Se{sub 2} (CIGS) surfaces have been demonstrated to exhibit excellent surface passivation properties, which is advantageous in reducing recombination losses at the rear metal contact of CIGS thin-film solar cells. Here, we report, for the first time, experimentally extracted electronic parameters, i.e. fixed charge density (Q{sub f}) and interface-trap charge density (D{sub it}), for as-deposited (AD) and post-deposition annealed (PDA) ALD Al{sub 2}O{sub 3} films on CIGS surfaces using capacitance–voltage (C-V) and conductance-frequency (G-f) measurements. These results indicate that the AD films exhibit positive fixed charges Q{sub f} (approximately 10{sup 12} cm{sup −2}), whereas the PDA films exhibit a very high density of negative fixed charges Q{sub f} (approximately 10{sup 13} cm{sup −2}). The extracted D{sub it} values, which reflect the extent of chemical passivation, were found to be in a similar range of order (approximately 10{sup 12} cm{sup −2} eV{sup −1}) for both AD and PDA samples. The high density of negative Q{sub f} in the bulk of the PDA Al{sub 2}O{sub 3} film exerts a strong Coulomb repulsive force on the underlying CIGS minority carriers (n{sub s}), preventing them to recombine at the CIGS/Al{sub 2}O{sub 3} interface. Using experimentally extracted Q{sub f} and D{sub it} values, SCAPS simulation results showed that the surface concentration of minority carriers (n{sub s}) in the PDA films was approximately eight-orders of magnitude lower than in the AD films. The electrical characterization and estimations presented in this letter construct a comprehensive picture of the interfacial physics involved at the Al{sub 2}O{sub 3}/CIGS interface.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Room-temperature fabrication of light-emitting thin films based on amorphous oxide semiconductor

We propose a light-emitting thin film using an amorphous oxide semiconductor (AOS) because AOS has low defect density even fabricated at room temperature. Eu-doped amorphous In-Ga-Zn-O thin films fabricated at room temperature emitted intense red emission at 614 nm. It is achieved by precise control of oxygen pressure so as to suppress oxygen-deficiency/excess-related defects and free carriers. An electronic structure model is proposed, suggesting that non-radiative process is enhanced mainly by defects near the excited states. AOS would be a promising host for a thin film phosphor applicable to flexible displays as well as to light-emitting transistors.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Characterization of MBE-grown InAlN/GaN heterostructure valence band offsets with varying In composition

Angle-resolved X-ray photoelectron spectroscopy (XPS) is used in this work to experimentally determine the valence band offsets of molecular beam epitaxy (MBE)-grown InAlN/GaN heterostructures with varying indium composition. We find that the internal electric field resulting from polarization must be taken into account when analyzing the XPS data. Valence band offsets of 0.12 eV for In{sub 0.18}Al{sub 0.82}N, 0.15 eV for In{sub 0.17}Al{sub 0.83}N, and 0.23 eV for In{sub 0.098}Al{sub 0.902}N with GaN are obtained. The results show that a compositional-depended bowing parameter is needed in order to estimate the valence band energies of InAlN as a function of composition in relation to those of the binary endpoints, AlN and InN.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

A stochastic model of solid state thin film deposition: Application to chalcopyrite growth

Developing high fidelity quantitative models of solid state reaction systems can be challenging, especially in deposition systems where, in addition to the multiple competing processes occurring simultaneously, the solid interacts with its atmosphere. In this work, we develop a model for the growth of a thin solid film where species from the atmosphere adsorb, diffuse, and react with the film. The model is mesoscale and describes an entire film with thickness on the order of microns. Because it is stochastic, the model allows us to examine inhomogeneities and agglomerations that would be impossible to characterize with deterministic methods. We demonstrate the modeling approach with the example of chalcopyrite Cu(InGa)(SeS){sub 2} thin film growth via precursor reaction, which is a common industrial method for fabricating thin film photovoltaic modules. The model is used to understand how and why through-film variation in the composition of Cu(InGa)(SeS){sub 2} thin films arises and persists. We believe that the model will be valuable as an effective quantitative description of many other materials systems used in semiconductors, energy storage, and other fast-growing industries.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

High-heat-load monochromator options for the RIXS beamline at the APS with the MBA lattice

With the MBA lattice for APS-Upgrade, tuning curves of 2.6 cm period undulators meet the source requirements for the RIXS beamline. The high-heat-load monochromator (HHLM) is the first optical white beam component. There are four options for the HHLM such as diamond monochromators with refrigerant of either water or liquid nitrogen (LN{sub 2}), and silicon monochromators of either direct or indirect cooling system. Their performances are evaluated at energy 11.215 keV (Ir L-III edge). The cryo-cooled diamond monochromator has similar performance as the water-cooled diamond monochromator because GaIn of the Cu-GaIn-diamond interface becomes solid. The cryo-cooled silicon monochromators perform better, not only in terms of surface slope error due to thermal deformation, but also in terms of thermal capacity.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

Analysis of low efficiency droop of semipolar InGaN quantum well light-emitting diodes by modified rate equation with weak phase-space filling effect

We study the low efficiency droop characteristics of semipolar InGaN light-emitting diodes (LEDs) using modified rate equation incoporating the phase-space filling (PSF) effect where the results on c-plane LEDs are also obtained and compared. Internal quantum efficiency (IQE) of LEDs was simulated using a modified ABC model with different PSF filling (n{sub 0}), Shockley-Read-Hall (A), radiative (B), Auger (C) coefficients and different active layer thickness (d), where the PSF effect showed a strong impact on the simulated LED efficiency results. A weaker PSF effect was found for low-droop semipolar LEDs possibly due to small quantum confined Stark effect, short carrier lifetime, and small average carrier density. A very good agreement between experimental data and the theoretical modeling was obtained for low-droop semipolar LEDs with weak PSF effect. These results suggest the low droop performance may be explained by different mechanisms for semipolar LEDs.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

First-principles determination of band-to-band electronic transition energies in cubic and hexagonal AlGaInN alloys

We provide approximate quasiparticle-corrected band gap energies for quaternary cubic and hexagonal Al{sub x}Ga{sub y}In{sub 1–x–y}N semiconductor alloys, employing a cluster expansion method to account for the inherent statistical disorder of the system. Calculated values are compared with photoluminescence measurements and discussed within the currently accepted model of emission in these materials by carrier localization. It is shown that bowing parameters are larger in the cubic phase, while the range of band gap variation is bigger in the hexagonal one. Experimentally determined transition energies are mostly consistent with band-to-band excitations.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Structural defects and recombination behavior of excited carriers in Cu(In,Ga)Se{sub 2} solar cells

The carriers’ behavior in neutral region (NTR) and space charged region (SCR) of Cu(In,Ga)Se{sub 2} thin film based solar cells has been investigated by temperature dependent photoluminescence (PL-T), electroluminescence (EL-T) and current-voltage (IV-T) from 10 to 300 K. PL-T spectra show that three kinds of defects, namely V{sub Se}, In{sub Cu} and (In{sub Cu}+V{sub Cu}), are localized within the band gap of NTR and SCR of CIGS layer, corresponding to the energy levels of E{sub C}-0.08, E{sub C}-0.20 and E{sub C}-0.25 eV, respectively. The In{sub Cu} and (In{sub Cu}+V{sub Cu}) deep level defects are non-radiative recombination centers at room temperature. The IV-T and EL-T analysis reveals that the injection modes of electrons from ZnO conduction band into Cu(In,Ga)Se{sub 2} layer are tunneling, thermally-excited tunneling and thermionic emission under 10-40, 60-160, and 180-300 K, respectively. At 10-160 K, the electrons tunnel into (In{sub Cu}+V{sub Cu}) and V{sub se} defect levels in band gap of SCR and the drifting is involved in the emission bands at 0.96 and 1.07 eV, which is the direct evidence for a tunneling assisted recombination. At 180-300 K, the electrons are directly injected into the Cu(In,Ga)Se{sub 2} conduction band, and the emission of 1.13 eV are ascribed to the transitions from the conduction band to the valence band.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Effect of thermal annealing on electron spin relaxation of beryllium-doped In{sub 0.8}Ga{sub 0.2}As{sub 0.45}P{sub 0.55} bulk

The effect of thermal annealing on the electron spin relaxation of beryllium-doped In{sub 0.8}Ga{sub 0.2}As{sub 0.45}P{sub 0.55} bulk was investigated by time-resolved spin-dependent pump and probe reflection measurement with a high time resolution of 200 fs. Three similar InGaAsP samples were examined one of which was annealed at 800 °C for 1 s, one was annealed at 700 °C for 1 s and the other was not annealed after crystal growth by molecular beam epitaxy. Although the carrier lifetimes of the 700 °C-annealed sample and the unannealed sample were similar, that of the 800 °C-annealed sample was extended to 11.6 (10.4) ns at 10 (300) K, which was more than two (four) times those of the other samples. However, interestingly the spin relaxation time of the 800 °C-annealed sample was found to be similar to those of the other two samples. Particularly at room temperature, the spin relaxation times are 143 ps, 147 ps, and 111 ps for the 800 °C-annealed sample, 700 °C-annealed sample, and the unannealed sample, respectively.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

Thin-Film In{sub x}Al{sub y}Ga{sub 1–} {sub x–} {sub y}As{sub z}Sb{sub 1–} {sub z}/GaSb Heterostructures Grown in a Temperature Gradient

The thin-film In{sub x}Al{sub y}Ga{sub 1–} {sub x–} {sub y}As{sub z}Sb{sub 1–} {sub z}/GaSb heterostructures have been grown from liquid phase in a temperature gradient. The growth kinetics, the composition, the structural perfection, and the luminescence properties of the InAlGaAsSb thin films grown on a GaSb substrate have been studied.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

Tellurium Solubility in TlGaTe{sub 2} and TlInTe{sub 2} and the Electrophysical Properties of Solid Solutions

The complex methods of the physicochemical analysis are used to study TlGaTe{sub 2}–Te and TlInTe{sub 2}–Te alloys in which the tellurium solubility region up to 5.0 at % is observed. The temperature dependences of the lattice parameters and the electrical conductivity of TlGaTe{sub 2+x} and TlInTe{sub 2+x} have been studied in different crystallographic directions. The TlGaTe{sub 2+x} and TlInTe{sub 2+x} solid solutions undergo a phase transition at a temperature of 498 K. The transition nature is interpreted.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

Lasing in 9.6-μm Quantum Cascade Lasers

Lasing in MBE-grown impulsively pumped quantum cascade lasers of 9.6 μm at 140 K has been demonstrated. The active area is based on three-phonon resonance scattering of electrons. An In{sub 0.53}Ga{sub 0.47}As/Al{sub 0.48}In{sub 0.52}As solid alloy heteropair was used to form periods of quantum cascade lasers. The upper In{sub 0.52}Al{sub 0.48}As cladding of the waveguide was made thick. Alloyed and unalloyed lower metallization systems were studied. The threshold current density for a ridge laser 1 mm long and 27 μm wide has been found to roughly equal 3 kA/cm{sup 2} at 87 K. The optical output power has been estimated at a level of 20–35 mW.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Characteristics of InGaAsBi with various lattice mismatches on InP substrate

To develop bismuth-containing infrared optoelectronic devices, InGaAsBi/InP films with different lattice mismatches have been investigated. The lattice mismatch was tailored by changing the Bi content in conjunction with the In content simultaneously. X-ray diffraction analysis revealed that alloy lattice constants have been extended positively by incorporation of Bi into the crystal lattice. Electrical and optical characteristics were investigated by Hall-effect, optical absorption and photoluminescence measurements. A bandgap shrinking of about 56.4 meV/Bi% was deduced by X-ray diffraction and optical absorption measurements. From the excitation dependent photoluminescence measurement at 10 K, the donor-acceptor pair emissions were inferred for samples containing moderate and high levels of Bi. The temperature dependence of the PL peak energy is as small as 0.06 meV/K in In{sub 0.5}Ga{sub 0.5}As{sub 0.987}Bi{sub 0.013}, which is fairly low compared with that of In{sub 0.5}Ga{sub 0.5}As.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Effect of top gate potential on bias-stress for dual gate amorphous indium-gallium-zinc-oxide thin film transistor

We report the abnormal behavior of the threshold voltage (V{sub TH}) shift under positive bias Temperature stress (PBTS) and negative bias temperature stress (NBTS) at top/bottom gate in dual gate amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs). It is found that the PBTS at top gate shows negative transfer shift and NBTS shows positive transfer shift for both top and bottom gate sweep. The shift of bottom/top gate sweep is dominated by top gate bias (V{sub TG}), while bottom gate bias (V{sub BG}) is less effect than V{sub TG}. The X-ray photoelectron spectroscopy (XPS) depth profile provides the evidence of In metal diffusion to the top SiO{sub 2}/a-IGZO and also the existence of large amount of In{sup +} under positive top gate bias around top interfaces, thus negative transfer shift is observed. On the other hand, the formation of OH{sup −} at top interfaces under the stress of negative top gate bias shows negative transfer shift. The domination of V{sub TG} both on bottom/top gate sweep after PBTS/NBTS is obviously occurred due to thin active layer.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗