Showing papers on "Antimonide published in 1995"

Continuous wave operation of inas/inasxsb1-x midinfrared lasers

Abstract: Effective band gaps of type‐II superlattices (SLs) can cover a wide infrared wavelength range, even beyond the narrowest band gap of any natural antimonide semiconductor alloys. This letter reports the first InAs/InAsxSb1−x type‐II SL lasers with cw, optically pumped operation up to 95 K. The stimulated emission results from spatially indirect transitions of relatively extended electron states in the InAs/InAsxSb1−x SL conduction band to the hole states that are localized in the InAsx Sb1−x layers. The lasing wavelength is around 3.3–3.4 μm. Equivalent threshold current densities are estimated to be 3.3 and 56 A/cm2 at sample temperatures of 5 and 95 K, respectively. The characteristic temperature (T0) is approximately 32 K. These results demonstrate that the InAs/InAsxSb1−x type‐II SL clad by AlAs0.16Sb0.84 ordered‐alloy layers is a promising material system for midwave infrared semiconductor lasers.

Ternary Antimonides LnTSb3 with Ln = La-Nd, Sm and T = V, Cr

Abstract: The title compounds were prepared by reaction of the elemental components. They crystallize in a new structure type, which was determined from single-crystal X -ray data of CeCrSb₃: Pbcm, a = 1310.8(3), b = 618.4(1), c = 607.9(1) pm, Z = 4, R = 0.029 for 648 structure factors and 32 variable parameters. The structure of the antimonide CeVSb₃ is isotypic: a = 1319.0(2), b = 623.92(8), c = 603.03(8) pm , R = 0.041 for 477 structure factors and 32 variables. The transition metal site and one of the three antimony sites were found to have partial occupancies resulting in the exact compositions CeV₀,₉₁₍₁₎Sb₂,₉₁₆₍₄₎ and CeCr₀,₉₀₁₍₉₎Sb₂,₉₀₉₍₄₎. The structures contain fractional Sb -Sb bonds with distances varying between 301,5 and 316.4 pm. The transition metal atoms have octahedral antimony coordination. These TSb₆ octahedra share faces resulting in linear infinite strings with V - V and Cr - Cr bond distances of 301.5 and 304.0 pm, respectively. The structure of these com pounds contains building elements, which are also found in antimonides with ThCr₂Si₂, CaBe₂Ge₂, and HfCuSi₂ type structures.

Heterojunction interband tunnel diodes with improved P/V current ratios

Abstract: A heterojunction tunnel diode with first and second barrier layers, the first barrier layer including aluminum antimonide arsenide. A quantum well formation is sandwiched between the first and second barrier layers, and includes first and second quantum well layers with a barrier layer sandwiched therebetween, the first quantum well layer being adjacent the first barrier layer. The first quantum well layer is gallium antimonide arsenide which produces a peak in hole accumulations therein. The second quantum well layer produces a peak in electron accumulations therein. A monolayer of gallium antimonide is sandwiched in the first quantum well layer at the peak in hole accumulations and a monolayer of indium arsenide is sandwiched in the second quantum well layer at the peak in electron accumulations.

Phase Transitions in III-V Compounds to Megabar Pressures

Abstract: The high pressure behavior of 16 I11-V semiconductors, including the nitride, phosphide, arsenide, and antimonide, respectively, of boron, aluminum, gallium and indium, is discussed in a summary of recent research efforts. The emphasis is laid on the structural phase transitions at high pressures utilizing X-ray diffraction technique. The equation of state (EOS) and, hence, the bulk modulus and its pressure derivative at 0 pressure of these compounds is also summarized. Theoretical results are compared with experimental data wherever appropriate to show an ever­ increasing reliability of theoretical predictions. Optical absorption, reflec­ tivity, and Raman measurements of these compounds are briefly mentioned. Two closely related IVB elements, Si and Ge, are also discussed.

Advances in infrared antimonide technology

Abstract: Recently, significant advances have been made in both the application and production of the narrow gap, antimonide compound semiconductors. Growth of InSb and GaSb at 3 and even 4 inch diameters has been achieved with good homogeneity and acceptable defect density. Advances are being made to achieve a wafer surface finish suitable for direct epitaxy. New binary applications for large-area focalplane detector arrays, high resistivity substrates and thermophotovoltaics, and for the ternary (Ga,In)Sb are discussed.

Ternary Antimonides LnTSb3 with Ln = La-Nd, Sm and T = V, Cr.

Abstract: The title compounds were prepared by reaction of the elemental components. They crystallize in a new structure type, which was determined from single-crystal X -ray data of CeCrSb₃: Pbcm, a = 1310.8(3), b = 618.4(1), c = 607.9(1) pm, Z = 4, R = 0.029 for 648 structure factors and 32 variable parameters. The structure of the antimonide CeVSb₃ is isotypic: a = 1319.0(2), b = 623.92(8), c = 603.03(8) pm , R = 0.041 for 477 structure factors and 32 variables. The transition metal site and one of the three antimony sites were found to have partial occupancies resulting in the exact compositions CeV₀,₉₁₍₁₎Sb₂,₉₁₆₍₄₎ and CeCr₀,₉₀₁₍₉₎Sb₂,₉₀₉₍₄₎. The structures contain fractional Sb -Sb bonds with distances varying between 301,5 and 316.4 pm. The transition metal atoms have octahedral antimony coordination. These TSb₆ octahedra share faces resulting in linear infinite strings with V - V and Cr - Cr bond distances of 301.5 and 304.0 pm, respectively. The structure of these com pounds contains building elements, which are also found in antimonides with ThCr₂Si₂, CaBe₂Ge₂, and HfCuSi₂ type structures.

Optical Characterization of Indium Arsenide Antimonide Semiconductors Grown by Molecular Beam Epitaxy

Abstract: : The material parameters and crystalline quality of undoped, MBE-grown InAs(1-x)Sb(x) nearly lattice-matched to (100) GaSb (-0.617% less than or equal delta a/a less than or equal +0.708%) similar to material used for mid-infrared semiconductor lasers were determined by optical characterization. Absorption measurements at temperatures between 6-295 K determined the energy gap and wavelength-dependent absorption coefficient for each sample. The compositional dependence of the energy gap was anomalous when compared to previously reported data, suggesting phase separation existed in the material. The samples were also studied by temperature- and excitation-dependent photoluminescence (PL), which, for the majority of cases, showed only a single band-edge peak, identified by comparison with the absorption data. PL linewidths as narrow as 4.3 meV and LO-phonon replicas indicated high material quality, but the shift of the PL peak to higher energies with increased excitation was greater than expected from band filling alone, and underscored the likelihood of phase separation. Extrinsic PL peaks were also observed from one undoped sample, and identified a F-B transition at 4-7 meV and a DAP transition at 10-14 meV below the band edge. Characterization of InAs(1-x)Sb(x):Be identified the Be acceptor energy as >30 meV above the valence band. jg p263

Fabrication of compound semiconductor element

Abstract: PURPOSE:To provide a method for easily fabricating a narrow, gap compound semiconductor element having infrared ray detecting function in which the compositional elements are bonded strongly to allow stabilized crystal growth. CONSTITUTION:The method for fabricating a compound semiconductor element comprises a step for epitaxially growing an tin-indium antimonide (Snx(InSb)1-x) layer 2 on a substrate 1 of indium antimonide (InSb) at a base body (substrate) temperature of 50-230 deg.C, and a step for forming a semiconductor element region (active region) on the tin-indium antimonide (Snx(InSb)1-x) layer 2.

2-µm GaSb-Based Distributed Bragg Reflector Lasers

Abstract: A rapidly expanding application of infrared diode lasers is trace-gas sensing using laser-absorption spectroscopy (LAS).1 Applications include pollution monitors in automobiles, semiconductor process control, glucose monitoring and the ex situ diagnosis of internal disorders by monitoring trace gases on human breath.2 For practical implementation of LAS lasers must operate near room temperature in a continuously tunable single longitudinal mode, with an important mid-infrared wavelength range of 2 - 5 μm. The antimonide materials can access 2-5 μm, and significant progress has been made recently. For example, molecular beam epitaxy (MBE)-grown multi-quantum well (MQW) room-temperature cw lasers emitting 2 - 2.4 μm were reported with threshold current densities of 143 A/cm2 and output powers of 1.3W.3 The longest emission wavelength reported thus far for GaSb-based lasers operating at room temperature is 2.78 μm.4