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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

X-Ray Study of the Superstructure in Heavily Doped Porous Indium Phosphide

An indium-phosphide InP sample subjected to the pore-generation procedure and then doped with S atoms is studied by the methods of X-ray diffraction analysis (XRD) and small-angle X-ray scattering (SAXS) (with CuK{sub α1}-radiation). The XRD data demonstrate that the sample consists of (coherent) aligned homogeneous components. A point detector is used to obtain, in the anomalous transmission mode by Borrmann, a set of SAXS curves at sample positions varied by azimuthal rotations. The SAXS data are used to simulate a 2D SAXS pattern for the sample under study, which makes it possible to determine the long-distance translation symmetry and, consequently, the presence of a superstructure. The interplanar distances in the superstructure in the directions (110) and (1 0) of the InP lattice are found to be ~260 and 450 nm, respectively. The symmetry group of the superstructure is determined as C{sub 2v} in the (001) plane of the sample lattice.

36 MATERIALS SCIENCE↗
DOE OSTI2018

4‐1: Invited Paper: Role of Phosphorus Oxidation in Controlling the Luminescent Properties of Indium Phosphide Quantum Dots

Indium phosphide (InP) is the leading Cd‐free quantum dot material for application in photoluminescence downconversion display and lighting technologies. To date the performance of InP quantum dots (QDs) has lagged behind cadmium selenide in terms of both luminescence line width and quantum yield. Extensive studies in our lab have implicated kinetically persistent magic‐sized cluster intermediates as a leading contributor to polydispersity in these samples, providing new opportunities for achieving high color purity. Now, using a combination of solid‐state NMR spectroscopy and recently developed benchtop X‐ray emission spectroscopy, we have studied the evolution of oxidized phosphorus species during both synthesis and shell growth.

Cossairt, Brandi M.↗
DOE OSTI2025

Expanding Parameter Space to Enable Low-Temperature Synthesis of Crystalline Indium Phosphide Quantum Dots

Established methods to synthesize indium phosphide quantum dots (QDs) require high temperatures (>180 °C) to make high-quality material for optoelectronic applications. Nonpolar solvent environments are overwhelmingly used in InP QD synthesis to reach the necessary high temperatures and for compatibility with the reactive precursors. In this study, we explored InP QD synthesis in polar aprotic solvent environments to dramatically decrease the temperature required for InP crystallization by imparting ionicity to the precursors and stabilizing charged reaction intermediates. A custom air-free 96- well plate setup was employed to identify key factors impacting low-temperature QD formation, including an increased percentage of polar solvent, carboxylic acid choice, and inclusion of polar additives. Guided by these insights, we developed a synthesis of crystalline, green-emitting InP QDs at 60 °C in a toluene-dimethylformamide mixture. Here's, the QDs withstood established Zn 2+ and HF surface treatments, which increased the photoluminescence quantum yield to 25%. Additionally, we demonstrated the rapid synthesis of quasi-wurtzite InP QDs at room temperature in a polar solvent environment using an acid-free indium myristate precursor.

absorption↗
DOE OSTI2016

Molybdenum Disulfide as a Protection Layer and Catalyst for Gallium Indium Phosphide Solar Water Splitting Photocathodes

Gallium indium phosphide (GaInP2) is a semiconductor with promising optical and electronic properties for solar water splitting, but its surface stability is problematic as it undergoes significant chemical and electrochemical corrosion in aqueous electrolytes. Molybdenum disulfide (MoS2) nanomaterials are promising to both protect GaInP2 and to improve catalysis since MoS2 is resistant to corrosion and also possesses high activity for the hydrogen evolution reaction (HER). In this work, we demonstrate that GaInP2 photocathodes coated with thin MoS2 surface protecting layers exhibit excellent activity and stability for solar hydrogen production, with no loss in performance (photocurrent onset potential, fill factor, and light limited current density) after 60 hours of operation. This represents a five-hundred fold increase in stability compared to bare p-GaInP2 samples tested in identical conditions.

14 SOLAR ENERGY↗
DOE OSTI2024

Novel indium phosphide charged particle detector characterization with a 120 GeV proton beam

Thin film detectors which incorporate semiconductor materials other than silicon have the potential to build upon their unique material properties and offer advantages such as faster response times, operation at room temperature, and radiation hardness. To explore the possibility, promising candidate materials were selected, and particle tracking detectors were fabricated. An indium phosphide detector with a metal-intrinsic-metal structure has been fabricated for particle tracking. The detector was tested using radioactive sources and a high energy proton beam at Fermi National Accelerator Laboratory. In addition to its simplistic design and fabrication process, the indium phosphide particle detector showed a very fast response time of hundreds of picoseconds for the 120 GeV protons, which are comparable to the ultra-fast silicon detectors. This fast-timing response is attributed to the high electron mobility of indium phosphide. Such material properties can be leveraged to build novel detectors with superlative performance.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

Extending the Near-Infrared Emission Range of Indium Phosphide Quantum Dots for Multiplexed In Vivo Imaging

This report of the reddest emitting indium phosphide quantum dots (InP QDs) to date demonstrates tunable, near-infrared (NIR) photoluminescence (PL) as well as PL multiplexing in the first optical tissue window while avoiding toxic constituents. This synthesis overcomes the InP “growth bottleneck” and extends the emission peak of InP QDs deeper into the first optical tissue window using an inverted QD heterostructure, specifically ZnSe/InP/ZnS core/shell/shell nanoparticles. The QDs exhibit InP shell thickness-dependent tunable emission with peaks ranging from 515–845 nm. The high absorptivity of InP yields effective photoexcitation of the QDs with UV, visible, and NIR wavelengths. These nanoparticles extend the range of tunable direct-bandgap emission from InP-based nanostructures, effectively overcoming a synthetic barrier that has prevented InPbased QDs from reaching their full potential as NIR imaging agents. Further, multiplexed lymph node imaging in a mouse model demonstrates the potential of the NIR-emitting InP particles for in vivo imaging.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2019

Interfacial engineering of gallium indium phosphide photoelectrodes for hydrogen evolution with precious metal and non-precious metal based catalysts

Gallium indium phosphide (GaInP 2 ) is a semiconductor with promising optical and electronic properties to serve as the large bandgap, top junction in a dual absorber tandem solar water splitting device. Poor intrinsic catalytic ability and surface corrosion in aqueous electrolyte remain key obstacles. Significant progress has been made developing thin-film protection layers and active catalysts for photoelectrochemical devices, but combining these into a catalytic protection layer that can provide long-term stability without sacrificing performance has proven difficult due, in large part, to challenges in developing active and stable interfaces. In this work, we demonstrate that a nanoscale molybdenum disulfide (MoS 2 ) film functions both as an effective protection layer and excellent hydrogen evolution catalyst for GaInP 2 photocathodes, with only a ~10% loss in initial light-limited current density after 100 h, and a photocurrent onset potential better than that of the same state-of-the-art device with a platinum-ruthenium catalyst. Using transient photoreflectance spectroscopy, we probed the carrier dynamics of these photocathodes and show that the MoS 2 coated device exhibits improved electron transfer at the surface interface compared to the PtRu catalyzed device. These MoS 2 protected devices are among the most active and stable single-absorber photocathodes for solar water splitting to date and offer a promising pathway towards generating hydrogen with high efficiency and significant longevity.

08 HYDROGEN↗
DOE OSTI2018

Electronic Structure and Dynamics of Copper-Doped Indium Phosphide Nanocrystals Studied with Time-Resolved X-ray Absorption and Large-Scale DFT Calculations

Here, the recent development of time-resolved X-ray absorption spectroscopy (TR-XAS) has opened avenues for fundamental research on doped semiconductors. Reported herein are results on the successful doping of indium phosphide nanocrystals (NCs) with copper and subsequent charactenzation with time-resolved X-ray studies and largescale density functional theory (DFT) calculations. The synthetic protocol that was based on the cluster seed method afforded control of both the doping level and the quantity of NCs produced in a batch. The stability of the colloidal dispersion allowed us to monitor the photophysical properties of copper guest ions with static and TR-XAS at the copper K-edge. These data reveal that copper captures a hole from the photoexcited InP NC, and relaxation to the ground state occurs via multiple timescales likely due to the presence of interior and surface-bound dopant ions as well as recombination with surfaceand defect-trapped electrons. Large-scale DFT calculations reveal a striking dependence of the electronic structure on the ligand coating and other effects such as self-compensation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Characterizing novel Indium Phosphide pad detectors with focused X-ray beams and laboratory tests

Future tracking systems in High Energy Physics experiments will require large instrumented areas with low radiation length. Crystalline silicon sensors have been used in tracking systems for decades, but are difficult to manufacture and costly to produce for large areas. We are exploring alternative sensor materials that are amenable to fast fabrication techniques used for thin film devices. Indium Phosphide pad sensors were fabricated at Argonne National Lab using commercially available InP:Fe 2-inch mono-crystal substrates. Current-voltage and capacitance-voltage characterizations were performed to study the basic operating characteristics of a group of sensors. Micro-focused X-ray beams at Canadian Light Source and Diamond Light Source were used to study the response to ionizing radiation, and characterize the uniformity of the response for several devices. Electrical test results showed a high degree of performance uniformity between the 48 tested devices. X-ray test beam results showed good performance uniformity within tested devices after accounting for spatially-local defects and edge fields. As a result, this motivates further studies into thin film devices for future tracking detectors.

47 OTHER INSTRUMENTATION↗
DOE OSTI2018

High-Quality Indium Phosphide Films and Nano-Network Grown Using Low-Cost Metal-Catalyzed Vapor-Liquid-Solid Method for Photovoltaic Applications

Growth of high-quality InP film is demonstrated by directly co-evaporating elemental In and P in a simple low-cost chemical vapor deposition (CVD) reactor. By exploring the interplay between the metal-assisted vapor–liquid–solid and vapor–solid mechanisms, the authors present the growth of highly stoichiometric InP thin films or nano-network in a wide range of growth temperature from 560 to 720 °C. Photoluminescence (PL) measurements reveal high optical quality of the as-grown InP film with PL bandwidth (≈49 meV) comparable to commercial InP wafer (≈41 meV). The versatility of this approach is demonstrated through successful growth of thin films on diverse substrates such as silicon, InP, and fused quartz. Additionally, the effects of catalysts are also studied by comparing growths based on Au-catalyst with In-self-catalyst (without Au). The temperature dependence study of Au-catalyzed growth shows that higher growth temperature results in formation of larger grain sizes and continuous void-free polycrystalline InP films. Preliminary solar cell devices are fabricated on a p-type silicon with an indium-tin-oxide contact layer. It is believed that the new growth strategy provides a simpler, lower cost (both precursors and substrates) approach for producing high-quality InP thin film for the fabrication of high efficiency, low-cost solar cells.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Water-Vapor-Mediated Close-Spaced Vapor Transport Growth of Epitaxial Gallium Indium Phosphide Films on Gallium Arsenide Substrates

Ga 1–x In x P is a technologically important III–V ternary semiconductor widely utilized in commercial and record-efficiency solar cells. We report the growth of Ga 1–x In x P by water-vapor-mediated close-spaced vapor transport. Because growth of III–V semiconductors in this system is controlled by diffusion of metal oxide species, we find that congruent transport from the mixed powder source requires complete annealing to form a single alloy phase. Growth from a fully alloyed source at water vapor concentrations of ~7000 ppm in H 2 at 850 °C affords smooth films with electron mobility of 1070 cm 2 V –1 s –1 and peak internal quantum efficiency of ~90% for carrier collection in a nonaqueous photoelectrochemical test cell.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Broadband Sensitization of Lanthanide Emission with Indium Phosphide Quantum Dots for Visible to Near-Infrared Downshifting

Semiconductor quantum dot (QD)-sensitized lanthanide ions hold significant promise in producing a broadly absorbing and sharply emitting luminophore, but their synthesis has proven to be difficult. We report the first synthesis of core/shell/shell InP/Ln x Y 1- x F 3 /ShF 3 (Ln = Yb, Nd; Sh = Lu, Y) nanocrystals that exhibit a broad visible absorption coupled to a sharp near-infrared emission. Moreover, this is the first report of Nd being coupled to a QD absorber. We characterize the system with a variety of electron microscopy and X-ray techniques that prove this unique structure. Optical measurements confirm the correlation of the Ln 3+ emission to the QD absorption, while the presence of a trap-state emission gives a clue as to the mechanism of energy transfer between the dot and the lanthanide.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

On the Properties of Isoparametric AlInGaAsP/InP Heterostructures

The effect of growth conditions on the structural perfection of AlInGaAsP/InP thin-film heterostructures is discussed. The key parameters determining the structural perfection and surface quality of thin AlInGaAsP epitaxial films grown on indium-phosphide substrates from the liquid phase in a temperature-gradient field are determined.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Defect formation during chlorine-based dry etching and their effects on the electronic and structural properties of InP/InAsP quantum wells

The general objective is the investigation of the defects formed by dry etching tools such as those involved in the fabrication of photonic devices with III–V semiconductors. Emphasis is put on plasma exposures with chlorine-based chemistries. In addition to identifying these defects and describing their effects on the electro-optic and structural properties, the long-term target would be to predict the impact on the parameters of importance for photonic devices, and possibly include these predictions in their design. The work is first centered on explaining the experimental methodology. This methodology starts with the design and growth of a quantum well structure on indium phosphide, including ternary indium arsenide/phosphide quantum wells with graded arsenic/phosphor composition. These samples have then been characterized by luminescence methods (photo- and cathodoluminescence), high-resolution transmission electron microscopy, and secondary ion mass spectrometry. As one of the parameters of importance in this study, the authors have also included the doping level. The samples have been exposed to the etching plasmas for “short” durations that do not remove completely the quantum wells, but change their optical signature. No masking layer with lithographic features was involved as this work is purely oriented to study the interaction between the plasma and the samples. A significant difference in the luminescence spectra of the as-grown undoped and doped samples is observed. A mechanism describing the effect of the built-in electric field appearing as a consequence of the doping profile is proposed. This mechanism involves quantum confined Stark effect and electric-field induced carrier escape from the quantum wells. In the following part, the effects of exposure to various chlorine-based plasmas were explored. Differences are again observed between the undoped and doped samples, especially for chemistries containing silicon tetrachloride. Secondary ion mass spectrometry indicates penetration of chlorine in the structures. Transmission electron microscopy is used to characterize the quantum well structure before and after plasma bombardment. By examining carefully the luminescence spectral properties, the authors could demonstrate the influence of the etching plasmas on the built-in electric field (in the case of doped samples), and relate it to some ionic species penetrating the structures. Etching plasmas involving both chlorine and nitrogen have also been studied. The etching rate for these chemistries is much slower than for some of the silicon tetrachloride based chemistries. Their effects on the samples are also very different, showing much reduced effect on the built-in electric field (for the doped samples), but significant blue-shifts of the luminescence peaks that the authors attributed to the penetration of nitrogen in the structures. Nitrogen, in interstitial locations, induces mechanical compressive stress that accounts for the blue-shifts. Finally, from the comparison between secondary ion mass spectrometry and luminescence spectra, the authors suggest some elements for a general mechanism involved in the etching by chloride-chemistries, in which a competition takes place between the species at the surface, active for the etching mechanism, and the species that penetrate the structure, lost for the etching process, but relevant in terms of impact on the electro-optic and structural features of the exposed materials.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Materials Data on InSn2P(H3C)8 by Materials Project

InPIn(CH3)2InCH3(SnCH3)2(Sn(CH3)2)3Sn(CH3)3(CH3)10(P)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two indium phosphide molecules; two indium, methyl- molecules; twenty methane molecules; four methylstannane molecules; four phosphine molecules; two In(CH3)2 clusters; six Sn(CH3)2 clusters; and two Sn(CH3)3 clusters. In each In(CH3)2 cluster, In1+ is bonded in a 2-coordinate geometry to two C4- and one H+0.92+ atom. There are one shorter (2.42 Å) and one longer (2.77 Å) In–C bond lengths. The In–H bond length is 2.44 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a 3-coordinate geometry to one In1+ and three H+0.92+ atoms. There are a spread of C–H bond distances ranging from 1.07–1.32 Å. In the second C4- site, C4- is bonded in a 3-coordinate geometry to one In1+ and three H+0.92+ atoms. There are a spread of C–H bond distances ranging from 1.10–1.13 Å. There are six inequivalent H+0.92+ sites. In the first H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the second H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the third H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the fourth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the fifth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one In1+ and one C4- atom. In the sixth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In each Sn(CH3)2 cluster, Sn2+ is bonded in a 2-coordinate geometry to two C4- atoms. There is one shorter (1.70 Å) and one longer (2.11 Å) Sn–C bond length. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a 4-coordinate geometry to one Sn2+ and three H+0.92+ atoms. There are a spread of C–H bond distances ranging from 0.90–1.54 Å. In the second C4- site, C4- is bonded in a distorted trigonal pyramidal geometry to one Sn2+ and three H+0.92+ atoms. There are a spread of C–H bond distances ranging from 1.08–1.54 Å. There are six inequivalent H+0.92+ sites. In the first H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the second H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the third H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the fourth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the fifth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the sixth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In each Sn(CH3)3 cluster, Sn2+ is bonded in a 5-coordinate geometry to three C4- and two H+0.92+ atoms. There are a spread of Sn–C bond distances ranging from 2.05–2.14 Å. There are one shorter (2.10 Å) and one longer (2.16 Å) Sn–H bond lengths. There are three inequivalent C4- sites. In the first C4- site, C4- is bonded in a 2-coordinate geometry to one Sn2+ and three H+0.92+ atoms. There are a spread of C–H bond distances ranging from 1.01–1.50 Å. In the second C4- site, C4- is bonded in a 4-coordinate geometry to one Sn2+ and three H+0.92+ atoms. There are a spread of C–H bond distances ranging from 1.04–1.50 Å. In the third C4- site, C4- is bonded in a 2-coordinate geometry to one Sn2+ and three H+0.92+ atoms. There are a spread of C–H bond distances ranging from 1.05–1.50 Å. There are nine inequivalent H+0.92+ sites. In the first H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the second H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the third H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one Sn2+ and one C4- atom. In the fourth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the fifth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the sixth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one Sn2+ and one C4- atom. In the seventh H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the eighth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom. In the ninth H+0.92+ site, H+0.92+ is bonded in a single-bond geometry to one C4- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Investigation of 2D photonic crystal structure based channel drop filter using quad shaped photonic crystal ring resonator for CWDM system

In this paper, the design & performance of two dimensional (2-D) photonic crystal structure based channel drop filter is investigated using quad shaped photonic crystal ring resonator. In this paper, Photonic Crystal (PhC) based on square lattice periodic arrays of Gallium Indium Phosphide (GaInP) rods in air structure have been investigated using Finite Difference Time Domain (FDTD) method and photonic band gap is being calculated using Plane Wave Expansion (PWE) method. The PhC designs have been optimized for telecommunication wavelength λ= 1571 nm by varying the rods lattice constant. The number of rods in Z and X directions is 21 and 20, with lattice constant 0.540 nm it illustrates that the arrangement of Gallium Indium Phosphide (GaInP) rods in the structure which gives the overall size of the device around 11.4 µm × 10.8 µm. The designed filter gives good dropping efficiency using 3.298, refractive index. The designed structure is useful for CWDM systems. This device may serve as a key component in photonic integrated circuits. The device is ultra compact with the overall size around 123 µm{sup 2}.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗