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in subjects: "Gallium Antimonides"

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AlGaAsSb/GaSb Distributed Bragg Reflectors Grown by Organometallic Vapor Phase Epitaxy

The first AlGaAsSb/GaSb quarter-wave distributed Bragg reflectors grown by metallic vapor phase epitaxy are reported. The peak reflectance is 96% for a 10-period structure.

Date: February 13, 2002

Creator: Wang, C. A.; Vineis, C. J. & Calawa, D. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Antimonide based devices for thermophotovoltaic applications

Thermophotovoltaic (TPV) devices have been fabricated using epitaxial ternary and quaternary layers grown on GaSb substrates. GaInSb ternary devices were grown by metalorganic vapor phase epitaxy (MOVPE) with buffer layers to accommodate the lattice mismatch, and GaInAsSb lattice-matched quaternaries were grown by MOVPE. Improved devices are obtained when optical absorption occurs in the p-layer due to the longer minority carrier diffusion length. Thick emitter p/n devices are limited by surfac… more

Date: December 1, 1998

Creator: Hitchcock, C. W.; Gutmann, R. J.; Borrego, J. M.; Bhat, I. B. & Charache, G. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Antimonide-Based Long-Wavelength Lasers on GaAs Substrates

We have investigated the use of GaAsSb in edge-emitting laser active regions, in order to obtain lasing near 1.3 {micro}m. Single quantum well GaAsSb devices display electroluminescence at wavelengths as long as 1.34 {micro}m, but substantial blueshifts occur under high injection conditions. GaAsSb single quantum well edge emitters have been obtained which lase at 1.275 {micro}m with a room-temperature threshold current density as low as 535 A/cm{sup 2}. Modification of the basic GaAsSb/GaAs st… more

Date: August 17, 2000

Creator: KLEM,JOHN F. & Blum, O.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Auger and Radiative Recombination Coefficients in 0.55 eV InGaAsSb

A radio-frequency (RF) photoreflectance technique, which senses changes in sample conductivity as carriers recombine following excitation by a laser pulse, has been used to measure the recombination parameters in 0.55 eV InGaAsSb lattice matched to GaSb. Doubly-capped lifetime structures with variable active layer thicknesses are used to extract the surface recombination velocity (SRV), while analysis of the samples with different doping concentrations is used to obtain Auger (C) and radiative … more

Date: August 4, 2004

Creator: Wang, C. A. & Nichols, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Bridgman growth and characterization of bulk single crystals of Ga{sub 1{minus}x}In{sub x}Sb for thermophotovoltaic applications

Thermophotovoltaic generation of electricity is attracting renewed attention due to recent advances in low bandgap (0.5--0.7 eV) III-V semiconductors. The use of mixed pseudo-binary compounds allows for the tailoring of the lattice parameter and the bandgap of the material. Conventional deposition techniques (i.e., epitaxy) for producing such ternary or quaternary materials are typically slow and expensive. Production of bulk single crystals of ternary materials, for example Ga{sub 1{minus}x}In… more

Date: December 1, 1997

Creator: Boyer, J. R. & Haines, W. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Bulk crystal growth of antimonide based III-V compounds for thermophotovoltaics applications

In this paper, the bulk growth of crack-free GaInSb and single phase GaInAsSb alloys are presented. A new class of III-V quasi-binary [A{sub III}B{sub V}]{sub 12{minus}x}[C{sub III}D{sub V}]{sub x} semiconductor alloys has been synthesized and bulk crystals grown from the melt for the first time. The present investigation is focused on the quasi-binary alloy (GaSb){sub 1{minus}x}(InAs){sub x} (0 < x < 0.05) due to its importance for thermophotovoltaic applications. The structural properties of … more

Date: October 1, 1998

Creator: Dutta, P. S.; Ostrogorsky, A. G. & Gutmann, R. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Bulk growth of GaSb and Ga{sub 1{minus}x}In{sub x}Sb

GaSb and InGaSb have been demonstrated to be suitable choices for high efficiency thermophotovoltaic (TPV) cells. Synthesis and growth of bulk GaSb single crystals and GaInSb polycrystals have been carried out by the vertical Bridgman technique, with a baffle immersed in the melt and by complete encapsulation of the melt by low melting temperature alkali halides or oxides. The critical roles of the baffle and the encapsulation are discussed. Efforts in obtaining device grade GaSb with superior … more

Date: May 1, 1997

Creator: Dutta, P. S.; Ostrogorsky, A. G. & Gutmann, R. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system

A thermophotovoltaic energy conversion device and a method for making the device are disclosed. The device includes a substrate formed from a bulk single crystal material having a bandgap (E{sub g}) of 0.4 eV < E{sub g} < 0.7 eV and an emitter fabricated on the substrate formed from one of a p-type and an n-type material. Another thermophotovoltaic energy conversion device includes a host substrate formed from a bulk single crystal material and lattice-matched ternary or quaternary III-V semico… more

Date: December 31, 1996

Creator: Charache, Greg W.; Baldasaro, Paul F. & Nichols, Greg J.

Item Type: Patent

Partner: UNT Libraries Government Documents Department

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Characteristics of GaAsSb single quantum well lasers emitting near 1.3 {micro}m

The authors report data on GaAsSb single quantum well lasers grown on GaAs substrates. Room temperature pulsed emission at 1.275 {micro}m in a 1,250 {micro}m-long device has been observed. Minimum threshold current densities of 535 A/cm{sup 2} were measured in 2000 {micro}m long lasers. The authors also measured internal losses of 2--5 cm{sup {minus}1}, internal quantum efficiencies of 30-38% and characteristic temperature T{sub 0} of 67--77 C. From these parameters a gain constant G{sub 0} of … more

Date: February 17, 2000

Creator: SPAHN,OLGA B. & KLEM,JOHN F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Characteristics of GaSb and GaInSb Layers Grown by Metalorganic Vapor Phase Epitaxy

GaInSb and GaSb layers have been grown on GaSb and GaAs substrates using metalorganic vapor phase epitaxy (MOVPE) with trimethylgallium, trimethylindium and trimethylantimony as the sources. As grown layers are p type with the carrier concentration in the mid 10{sup 16} cm{sup {minus}3} range. N type layers are grown using diethyltellurium as the Te source. Incorporation of Te in high concentration showed compensation and secondary ion mass spectrometry (SIMS) result showed that only 2.5% of Te… more

Date: July 1, 1995

Creator: Ehsani, H.; Bhat, I.; Hitchcock, C.; Borrego, J. & Gutmann, R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Characterization of Recombination Processes in Epitaxial Thin Films and Substrates for Antimonide Based Thermophotovoltaic Devices

Recombination processes in antimonide-based materials for thermophotovoltaic (TPV) devices have been investigated using a radio-frequency (RF) photoreflectance technique, in which a Nd-YAG pulsed laser is used to excite excess carriers, and the short-pulse response and photoconductivity decay are monitored with an inductively-coupled non-contacting RF probe. Double-capped lattice-matched GaInAsSb organometallic vapor phase epitaxy (OMVPE)--grown layers on GaSb substrates have been used to evalu… more

Date: June 1, 1998

Creator: Saroop, S.; Borrego, J.; Gutmann, R.; Dutta, P.; Ostrogorsky, A.; Charache, G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Current status of low-temperature radiator thermophotovoltaic devices

The current performance status of low-temperature radiator (< 1,000 C) thermophotovoltaic (TPV) devices is presented. For low-temperature radiators, both power density and efficiency are equally important in designing an effective TPV system. Comparisons of 1 cm x 1 cm, 0.55 eV InGaAs and InGaAsSb voltaic devices are presented. Currently, InGaAs lattice-mismatched devices offer superior performance in comparison to InGaAsSb lattice-matched devices, due to the former`s long-term development for … more

Date: May 1, 1996

Creator: Charache, G. W.; Egley, J. L.; Danielson, L. R.; DePoy, D. M.; Baldasaro, P. F.; Campbell, B. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Czochralski growth of gallium indium antimonide alloy crystals

Attempts were made to grow alloy crystals of Ga{sub 1{minus}x}In{sub x}Sb by the conventional Czochralski process. A transparent furnace was used, with hydrogen purging through the chamber during crystal growth. Single crystal seeds up to about 2 to 5 mole% InSb were grown from seeds of 1 to 2 mole% InSb, which were grown from essentially pure GaSb seeds of the [111] direction. Single crystals were grown with InSb rising from about 2 to 6 mole% at the seed ends to about 14 to 23 mole% InSb at t… more

Date: February 1, 1998

Creator: Tsaur, S.C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Effect of Inert Gas Additive Species on Cl(2) High Density Plasma Etching of Compound Semiconductors: Part 1. GaAs and GaSb

The role of the inert gas additive (He, Ar, Xe) to C12 Inductively Coupled Plasmas for dry etching of GaAs and GaSb was examined through the effect on etch rate, surface roughness and near-surface stoichiometry. The etch rates for both materials go through a maximum with Clz 0/0 in each type of discharge (C12/'He, C12/Ar, C12/Xc), reflecting the need to have efficient ion-assisted resorption of the etch products. Etch yields initially increase strongly with source power as the chlorine neutral … more

Date: December 23, 1998

Creator: Abernathy, C.R.; Cho, H.; Hahn, Y.B.; Hays, D.C.; Jung, K.B.; Pearton, S.J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effect of Inert Gas Additive Species on Cl(2) High Density Plasma Etching of Compound Semiconductors: Part II. InP, InSb, InGaP and InGaAs

The effects of the additive noble gases He, Ar and Xe on chlorine-based Inductively Coupled Plasma etching of InP, InSb, InGaP and InGaAs were studied as a function of source power, chuck power and discharge composition. The etch rates of all materials with C12/He and C12/Xe are greater than with C12/Ar. Etch rates in excess of 4.8 pndmin for InP and InSb with C12/He or C12/Xe, 0.9 pndmin for InGaP with C12/Xe, and 3.8 prdmin for InGaAs with Clz/Xe were obtained at 750 W ICP power, 250 W rf pow… more

Date: December 17, 1998

Creator: Abernathy, C.R.; Cho, H.; Hahn, Y.B.; Hays, D.C.; Jung, K.B.; Pearton, S.J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Extending the cutoff wavelength of lattice-matched GaInAsSb/GaSb thermophotovoltaics devices

This paper reports the growth, materials characterization, and device performance of lattice-matched GaInAsSb/GaSb thermophotovoltaic (TPV) devices with cutoff wavelength as long as 2.5 {micro}m. GaInAsSb epilayers were grown lattice matched to GaSb substrates by organometallic vapor phase epitaxy (OMVPE) using all organometallic precursors including triethylgallium, trimethylindium, tertiarybutylarsine, and trimethylantimony with diethyltellurium and dimethylzinc as the n- and p-type dopants, … more

Date: October 1, 1998

Creator: Wang, C. A.; Choi, H. K.; Oakley, D. C. & Charache, G. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fabrication and Characterization of GaSb Based Thermophotovoltaic Cells Using Zn Diffusion from a Doped Spin-On Glass Source

The GaInSb material system is attractive for application in thermophotovoltaic (TPV) cells since its band gap can be tuned to match the radiation of the emitter. At present, most of the TPV cells are fabricated using epitaxial layers and hence are expensive. To reduce the cost, Zn diffusion using elemental vapors in a semi-closed diffusion system is being pursued by several laboratories. In this paper, the authors present studies carried out on Zn diffusion into n-type (Te-doped) GaSb substrate… more

Date: June 1, 1998

Creator: Dakshinamurthy, S.; Shetty, S.; Bhat, I.; Hitchcock, C.; Gutmann, R.; Charache, G. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Final Report: Bandgap-Engineered Thermophotovoltaic Devices for Hi Efficiency Radioisotope Power, July 9, 1996 - July 8, 1999

During Phase I the feasibility of fabricating high-performance, low bandgap (0.58ev)PV cells by thermally diffusing p-n junctions in GaSb based quaternary materials was established. During phase II, bandgap engineered thermophotovoltaic (TPV) cells were optimized, development of a low-cost build source material for quaternary devices was investigated, and a diesel-fueled, TPV test-bed was built and tested allowing its performance to be characterized.

Date: March 15, 2000

Creator: Sundaram, V; Morgan, M.D. & Horne, W.E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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GaAsSb/InGaAs type-II quantum wells for long-wavelength lasers on GaAs substrates

The authors have investigated the properties of GaAsSb/InGaAs type-II bilayer quantum well structures grown by molecule beam epitaxy for use in long-wavelength lasers on GaAs substrates. Structures with layer, strains and thicknesses designed to be thermodynamically stable against dislocation formation exhibit room-temperature photoluminescence at wavelengths as long as 1.43 {mu}m. The photoluminescence emission wavelength is significantly affected by growth temperature and the sequence of laye… more

Date: March 15, 2000

Creator: Klem, John F.; Spahn, Olga B.; Kurtz, Steven R.; Fritz, Ian J. & Choquette, Kent D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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GaInAsSb/AlGaAsSb/GaSb Thermophotovoltaic Devices

No Description Available.

Date: January 29, 2004

Creator: Wang, C. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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GaInAsSb materials for thermophotovoltaics

Ga{sub 1{minus}x}In{sub x}As{sub 1{minus}y}Sb{sub y} (0.06 < x < 0.2, 0.05 < y < 0.18) epilayers were grown lattice-matched to GaSb substrates by organometallic vapor phase epitaxy (OMVPE) and molecular beam epitaxy (MBE). For lattice-matched alloys, mirror-like surface morphologies were obtained by both OMVPE and MBE. The 4K photoluminescence (PL) of all layers had a full-width at half-maximum (FWHM) of less than 10 meV for PL peak emission < 1.9 {micro}m. PL FWHM increased to 30 meV for peak … more

Date: December 1, 1996

Creator: Wang, C. A.; Turner, G. W.; Manfra, M. J.; Choi, H. K. & Spears, D. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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GaInSb and GaInAsSb Thermophotovoltaic Device Fabrication and Characterization

Thermophotovoltaic (TPV) devices have been fabricated using epitaxial ternary and quaternary layers grown on GaSb substrates. The GaInSb layers were grown by organometallic vapor phase epitaxy (OMVPE) and the InGaAsSb lattice-matched layers were grown by liquid phase epitaxy (LPE). Device fabrication steps include unannealed p-type ohmic contacts, annealed Sn/Au n-type ohmic contacts, and a thick Ag top-surface contact using a lift-off process. Devices are characterized primarily by dark I-V, p… more

Date: May 1, 1997

Creator: Hitchcock, C.; Gutmann, R.; Borrego, J.; Ehsani, H.; Bhat, I.; Freeman, M. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Growth and characterization of In{sub 0.2}Ga{sub 0.8}Sb device structures using metalorganic vapor phase epitaxy

In{sub 0.2}Ga{sub 0.8}Sb epitaxial layers and thermophotovoltaic (TPV) device structures have been grown on GaSb and GaAs substrates by metalorganic vapor phase epitaxy (MOVPE). Control of the n-type doping up to 1 {times} 10{sup 18} cm{sup {minus}3} was achieved using diethyltellurium (DETE) as the dopant source. A Hall mobility of greater than 8,000 cm{sup 2}/Vs at 77 K was obtained for a 3 {times} 10{sup 17} cm{sup {minus}3} doped In{sub 0.2}Ga{sub 0.8}Sb layer grown on high-resistivity GaSb… more

Date: May 1, 1997

Creator: Ehsani, H.; Bhat, I.; Hitchcock, C.; Gutmann, R.; Charache, G. & Freeman, M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Growth and Characterization of Quantum Dots and Quantum Dots Devices

Quantum dot nanostructures were investigated experimentally and theoretically for potential applications for optoelectronic devices. We have developed the foundation to produce state-of-the-art compound semiconductor nanostructures in a variety of materials: In(AsSb) on GaAs, GaSb on GaAs, and In(AsSb) on GaSb. These materials cover a range of energies from 1.2 to 0.7 eV. We have observed a surfactant effect in InAsSb nanostructure growth. Our theoretical efforts have developed techniques to lo… more

Date: April 1, 2003

Creator: CEDERBERG, JEFFREY G.; BIEFELD, ROBERT M.; SCHNEIDER, H.C. & CHOW, WENG W.

Item Type: Report

Partner: UNT Libraries Government Documents Department