Center for Quantum Devices - Most Downloaded Journal Articles

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16.	High-responsivity GaInAs/InP Quantum Well Infrared Photodetectors Grown by Low-Pressure Metalorganic Chemical Vapor Deposition M. Erdtmann, A. Matlis, C. Jelen, M. Razeghi, and G. Brown SPIE Conference, San Jose, CA, -- January 26, 2000 ...[Visit Journal] We have studied the dependence of the well doping density in n-type GaInAs/InP quantum well IR photodetectors (QWIPs) grown by low-pressure metalorganic chemical vapor deposition. Three identical GaInAs/InP QWIP structures were grown with well sheet carrier densities of 1x10¹¹ cm^-2, 3x10¹¹ cm^-2, and 10x10¹¹ cm^-2; all three samples had very sharp spectral response at λ equals 9.0 μm. We find that there is a large sensitivity of responsivity, dark current, noise current, and detectivity with the well doping density. Measurements revealed that the lowest-doped samples had an extremely low responsivity relative to the doping concentration while the highest-doped sample had an excessively high dark current relative to doping. The middle-doped sample yielded the optimal results. This QWIP had a responsivity of 33.2 A/W and operated with a detectivity of 3.5x10¹⁰ cm·Hz^½·W^-1 at a bias of 0.75 V and temperature of 80 K. This responsivity is the highest value reported for any QWIP in the (lambda) equals 8-9 &mus;m range. Analysis is also presented explaining the dependence of the measured QWIP parameters to well doping density. [reprint (PDF)]
16.	Quantum-Cascade Lasers Operating in Continuous-Wave Mode Above 90°C at λ ~5.25 µm A. Evans, J. Nguyen, S. Slivken, J.S. Yu, S.R. Darvish, and M. Razeghi Applied Physics Letters 88 (5)-- January 30, 2006 ...[Visit Journal] We report on the design and fabrication of λ~5.25 μm quantum-cascade lasers (QCLs) for very high temperature continuous-wave (CW) operation. CW operation is reported up to a maximum temperature of 90 °C (363 K). CW output power is reported in excess of 500 mW near room temperature with a low threshold current density. A finite element thermal model is used to investigate the G_th and maximum CW operating temperature of the QCLs. [reprint (PDF)]
16.	Generalized k·p perturbation theory for atomic-scale superlattices H. Yi and M. Razeghi Physical Review B 56 (7)-- August 15, 1997 ...[Visit Journal] We present a generalized k⋅p perturbation method that is applicable for atomic-scale superlattices. The present model is in good quantitative agreement with full band theories with local-density approximation, and approaches results of the conventional k⋅p perturbation method (i.e., Kane’s Hamiltonian) with the envelope function approximation for superlattices with large periods. The indirect band gap of AlAs/GaAs superlattices with short periods observed in experiments is explained using this method. [reprint (PDF)]
16.	EPR STUDY OF Mn 2. AROUND THE FERROELASTIC TRANSITION POINT OF Pb3(PO4)2 M. Razeghi, B. Houlier and M. Yuste M. Razeghi et al. EPR STUDY OF Mn 2. AROUND THE FERROELASTIC TRANSITION POINT OF Pb3(PO4)2, Solid State Communications, Vol. 26, pp. 665-668. -- January 26, 1978 ...[Visit Journal] The spin Hamiltonian parameters of Mn 2÷ have been measured above and below the transition point (180"C) of the lead phosphate. They show that Mn 2+ substitutes a Pbl ion. Between 175 and 180vC the principal axis OX of the fine tensor is parallel to the wave vector of the soft mode which condensates at the transition point. An exaltation of the linewidth is observed. The linewidth remains constant within 50C of Te; in this temperature range, the "static regime" is achieved, and the correlation time of the fluctuations is less than 10 -s sec. [reprint (PDF)]
16.	Investigation of MgZnO/ZnO heterostructures grown on c-sapphire substrates by pulsed laser deposition D. J. Rogers ; F. Hosseini Teherani ; P. Bove ; A. Lusson ; M. Razeghi Proc. SPIE 8626, Oxide-based Materials and Devices IV, 86261X (March 18, 2013)-- March 18, 2013 ...[Visit Journal] MgZnO thin films were grown on c-sapphire and ZnO-coated c-sapphire substrates by pulsed laser deposition from a ZnMgO target with 4 at% Mg. The MgZnO grown on the ZnO underlayer showed significantly better crystal quality than that grown directly on sapphire. AFM studies revealed a significant deterioration in surface morphology for the MgZnO layers compared with the ZnO underlayer. Optical transmission studies indicated a MgZnO bandgap of 3.61eV (compared with 3.34eV for the ZnO), which corresponds to a Mg content of about 16.1 at%. The MgZnO/ZnO heterojunction showed an anomalously low resistivity, which was more than two orders of magnitude less than the MgZnO layer and an order of magnitude lower than that for the ZnO layer. It was suggested that this may be attributable to the presence of a 2D electron gas at the ZnMgO/ZnO heterointerface. [reprint (PDF)]
16.	Modeling the electronic band-structure of strained long-wavelength Type-II superlattices using the scattering matrix method Abbas Haddadi，Gail Brown，Manijeh Razeghi J Infrared Millim W 44 (3), 346 (2025) ...[Visit Journal] This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-II superlattices. Utilizing an eight-band k ⋅ p Hamilto⁃ nian in conjunction with a scattering matrix method， the model effectively incorporates quantum confinement， strain effects， and interface states. This robust and numerically stable approach achieves exceptional agreement with experimental data， offering a reliable tool for analyzing and engineering the band structure of complex multi⁃ layer systems [reprint (PDF)]
16.	High-Power Distributed-Feedback Quantum Cascade Lasers W.W. Bewley, I. Vurgaftman, C.S. Kim, J.R. Meyer, J. Nguyen, A.J. Evans, J.S. Yu, S.R. Darvish, S. Slivken and M. Razeghi SPIE Conference, San Jose, CA, Vol. 6127, pp. 612704-- January 23, 2006 ...[Visit Journal] Recently, a distributed-feedback quantum cascade laser operating in a single spectral mode at 4.8 µm and at temperatures up to 333 K has been reported. In the present work, we provide detailed measurements and modeling of its performance characteristics. The sidemode suppression ratio exceeds 25 dB, and the emission remains robustly single-mode at all currents and temperatures tested. Cw output powers of 99 mW at 298 K and 357 mW at 200 K are obtained at currents well below the thermal rollover point. [reprint (PDF)]
16.	Development of Quantum Cascade Lasers for High Peak Output Power and Low Threshold Current Density S. Slivken and M. Razeghi Solid State Electronics 46-- January 1, 2002 ...[Visit Journal] Design and material optimization are used to both decrease the threshold current density and increase the output power for quantum cascade lasers. Waveguides are designed to try and minimize free-carrier and surface-plasmon absorption. Excellent material characterization is also presented, showing excellent control over layer thickness, interface quality, and doping level. Experiments are done to both optimize the injector doping level and to maximize the output power from a single aperture. At 300 K, a threshold current density as low as 1.8 kA/cm² is reported, along with peak powers of approximately 2.5 W. Strain-balanced lasers are also demonstrated at λnot, vert, similar5 μm, exhibiting threshold current densities<300 A/cm² at 80 K. These values represent the state-of-the-art for mid-infrared lasers with λ>4 μm [reprint (PDF)]
16.	Etching of ZnO Towards the Development of ZnO Homostructure LEDs K. Minder, F.H. Teherani, D. Rogers, C. Bayram, R. McClintock, P. Kung, and M. Razeghi SPIE Conference, January 25-29, 2007, San Jose, CA Proceedings – Zinc Oxide Materials and Devices II, Vol. 6474, p. 64740Q-1-6-- January 29, 2007 ...[Visit Journal] Although ZnO has recently gained much interest as an alternative to the III-Nitride material system, the development of ZnO based optoelectonic devices is still in its infancy. Significant material breakthroughs in p-type doping of ZnO thin films and improvements in crystal growth techniques have recently been achieved, making the development of optoelectonic devices possible. First, a survey of current ZnO processing methods is presented, followed by the results of our processing research. [reprint (PDF)]
16.	High Quality Aluminum Nitride Epitaxial Layers Grown on Sapphire Substrates A. Saxler, P. Kung, C.J. Sun, E. Bigan and M. Razeghi Applied Physics Letters 64 (3)-- January 17, 1994 ...[Visit Journal] In this letter we report the growth of high quality AlN epitaxial layers on sapphire substrates. The AlN grown on (00·1) sapphire exhibited a better crystalline quality than that grown on (01·2) sapphire. An x-ray rocking curve of AlN on (00·1) Al₂O₃ yielded a full width at half-maximum of 97.2 arcsec, which is the narrowest value reported to our knowledge. The AlN peak on (01·2) Al₂O₃ was about 30 times wider. The absorption edge measured by ultraviolet transmission spectroscopy for AlN grown on (00·1) Al₂O₃ was about 197 nm. [reprint (PDF)]
16.	Al_xGa_1-xN (0 ≤ x ≤ 1) Ultraviolet Photodetectors Grown on Sapphire by Metal-organic Chemical-vapor Deposition D. Walker, X. Zhang, A. Saxler, P. Kung, J. Xu, and M. Razeghi Applied Physics Letters 70 (8)-- February 24, 1997 ...[Visit Journal] Al_xGa_1–xN (0 ≤ x ≤ 1) ultraviolet photoconductors with cutoff wavelengths from 365 to 200 nm have been fabricated and characterized. The maximum detectivity reached 5.5 × 10⁸ cm·Hz^1/2/W at a modulating frequency of 14 Hz. The effective majority carrier lifetime in Al_xGa_1–xN materials, derived from frequency-dependent photoconductivity measurements, has been estimated to be from 6 to 35 ms. The frequency-dependent noise spectrum shows that it is dominated by Johnson noise at high frequencies for low-Al-composition samples. [reprint (PDF)]
16.	Microstructural compositional, and optical characterization of GaN grown by metal organic vapor phase epitaxy on ZnO epilayers D.J. Rogers, F. Hosseini Teherani, T. Moudakir, S. Gautier, F. Jomard, M. Molinari, M. Troyon, D. McGrouther, J.N. Chapman, M. Razeghi and A. Ougazzaden Journal of Vacuum Science and Technology B, Vol. 27, No. 3, May/June, p. 1655-1657-- May 29, 2009 ...[Visit Journal] This article presents the results of microstructural, compositional, and optical characterization of GaN films grown on ZnO buffered c-sapphire substrates. Transmission electron microscopy showed epitaxy between the GaN and the ZnO, no degradation of the ZnO buffer layer, and no evidence of any interfacial compounds. Secondary ion mass spectroscopy revealed negligible Zn signal in the GaN layer away from the GaN/ZnO interface. After chemical removal of the ZnO, room temperature (RT) cathodoluminescence spectra had a single main peak centered at ~ 368 nm (~3.37 eV), which was indexed as near-band-edge (NBE) emission from the GaN layer. There was no evidence of the ZnO NBE peak, centered at ~379 nm (~3.28 eV), which had been observed in RT photoluminescence spectra prior to removal of the ZnO. [reprint (PDF)]
16.	Progress in monolithic, broadband, widely tunable midinfrared quantum cascade lasers Manijeh Razeghi Wenjia Zhou Ryan McClintock Donghai Wu Steven Slivken Optical Engineering 57(1), 011018-- December 1, 2017 ...[Visit Journal] We present recent progress on the development of monolithic, broadband, widely tunable midinfrared quantum cascade lasers. First, we show a broadband midinfrared laser gain realized by a heterogeneous quantum cascade laser based on a strain balanced composite well design of Al_0.63In_0.37As∕Ga_0.35In_0.65As∕ Ga_0.47In_0.53As. Single mode emission between 5.9 and 10.9 μm under pulsed mode operation was realized from a distributed feedback laser array, which exhibited a flat current threshold across the spectral range. Using the broadband wafer, a monolithic tuning between 6.2 and 9.1 μm was demonstrated from a beam combined sampled grating distributed feedback laser array. The tunable laser was utilized for a fast sensing of methane under pulsed operation. Transmission spectra were obtained without any moving parts, which showed excellent agreement to a standard measurement made by a Fourier transform infrared spectrometer. [reprint (PDF)]
16.	Type II superlattice infrared detectors and focal plane arrays Vaidya Nathan; Manijeh Razeghi Proc. SPIE 6542, Infrared Technology and Applications XXXIII, 654209 (May 14, 2007)-- May 14, 2007 ...[Visit Journal] Type II superlattce photodetectors have recently experienced significant improvements in both theoretical structure design and experimental realization. Empirical Tight Binding Method is initiated and developed for Type II superlattice. Growth characteristics such as group V segregation and incorporation phenomena are taken into account in the model and shown higher precision. A new Type II structure, called M-structure, is introduced and theoretically demonstrated high R₀A, high quantum efficiency. Device design is optimized to improve the performance. As a result, 55% quantum efficiency and 10 Ohm·cm² R₀A are achieved for an 11.7 μm cut-off photodetector at 77K. FPA imaging at longwavelength is demonstrated with a capability of imaging up to 171K. At 81K, the noise equivalent temperature difference presented a peak at 0.33K. [reprint (PDF)]
16.	Intersubband hole absorption in GaAs-GaInP Quantum Wells grown by Gas Source Molecular Beam Epitaxy J. Hoff, C. Jelen, S. Slivken, E. Michel, O. Duchemin, E. Bigan, and M. Razeghi with G. Brown and S.M. Hegde (Wright Laboratory) Applied Physics Letters 65 (9)-- August 29, 1994 ...[Visit Journal] P-doped GaAs‐GaInP quantum wells have been grown on GaAs substrate by gas source molecular beam epitaxy. Structural quality has been evidenced by x-ray diffraction. A narrow low-temperature photoluminescence full width at half‐maximum has been measured. Strong hole intersubband absorption has been observed at 9 μm, and its dependence on light polarization has been investigated. [reprint (PDF)]
16.	Pulsed metalorganic chemical vapor deposition of high quality AlN/GaN superlattices for intersubband transitions C. Bayram, B. Fain, N. Pere-Laperne, R. McClintock and M. Razeghi SPIE Proceedings, San Jose, CA Volume 7222-12-- January 26, 2009 ...[Visit Journal] A pulsed metalorganic chemical vapor deposition (MOCVD) technique, specifically designed for high quality AlN/GaN superlattices (SLs) is introduced. Optical quality and precise controllability over layer thicknesses are investigated. Indium is shown to improve interface and surface quality. An AlN/GaN SL designed for intersubband transition at a telecommunication wavelength of ~1.5 µm, is grown, and processed for intersubband (ISB) absorption measurements. Room temperature measurements show intersubband absorption centered at 1.49 µm. Minimal (n-type) silicon doping of the well is shown to be crucial for good ISB absorption characteristics. The potential to extend this technology into the far infrared and even the terahertz (THz) region is also discussed. [reprint (PDF)]
16.	Long-term reliability of Al-free InGaAsP/GaAs λ = 808 nm) lasers at high-power high-temperature operation J. Diaz, H. Yi, M. Razeghi and G.T. Burnham Applied Physics Letters 71 (21)-- November 24, 1997 ...[Visit Journal] We report the long-term reliability measurement on uncoated Al-free InGaAsP/GaAs (λ = 808 nm) lasers at high-power and high-temperature operation. No degradation in laser performance has been observed for over 30 ,000 h of lifetime testing in any of randomly selected several 100 μm-wide uncoated lasers operated at 60 °C with 1 W continuous wave output power. This is the first and the most conclusive evidence ever reported that directly shows the high long-term reliability of uncoated Al-free lasers. [reprint (PDF)]
16.	Mid-wavelength infrared heterojunction phototransistors based on type-II InAs/AlSb/GaSb superlattices A. Haddadi, S. Adhikary, A. Dehzangi, and M. Razeghi Applied Physics Letters 109, 021107-- July 12, 2016 ...[Visit Journal] A mid-wavelength infrared heterojunction phototransistor based on type-II InAs/AlSb/GaSb superlattices on GaSb substrate has been demonstrated. Near a wavelength of 4 μm saturated optical gains of 668 and 639 at 77 and 150 K, respectively, are demonstrated over a wide dynamic range. At 150 K, the unity optical gain collector dark current density and DC current gain are 1 × 10⁻³ A/cm² and 3710, respectively. This demonstrates the potential for use in high-speed applications. In addition, the phototransistor exhibits a specific detectivity value that is four times higher compared with a state-of-the-art type-II superlattice-based photodiode with a similar cut-off wavelength at 150 K. [reprint (PDF)]
16.	High Performance Solar-Blind Ultraviolet Focal Plane Arrays Based on AlGaN Erdem Cicek, Ryan McClintock, Abbas Haddadi, William A. Gaviria Rojas, and Manijeh Razeghi IEEE Journal of Quantum Electronics, Vol. 50, Issue 8, p 591-595-- August 1, 2014 ...[Visit Journal] We report on solar-blind ultraviolet, AlxGa1-x N- based,p-i-n,focal plane array (FPA) with 92% operability. At the peak detection wavelength of 278 nm, 320×256-FP A-pixel showed unbiased peak external quantum efficiency (EQE) and responsivity of 49% and 109 mA/W, respectively, increasing to 66% under 5 volts of reverse bias. Electrical measurements yielded a low-dark current density: <7×10^-9A/cm², at FPA operating voltage of 2 volts of reverse bias. [reprint (PDF)]
16.	High-speed free-space optical communications based on quantum cascade lasers and type-II superlattice detectors Stephen M. Johnson; Emily Dial; M. Razeghi Proc. SPIE 11288, Quantum Sensing and Nano Electronics and Photonics XVII, 1128814-- January 31, 2020 ...[Visit Journal] Free-space optical communications (FSOC) is a promising avenue for point-to-point, high-bandwidth, and high-security communication links. It has the potential to solve the “last mile” problem modern communication systems face, allowing for high-speed communication links without the expensive and expansive infrastructure required by fiber optic and wireless technologies 1 . Although commercial FSOC systems currently exist, due to their operation in the near infrared and short infrared ranges, they are necessarily limited by atmospheric absorption and scattering losses 2 . Mid-infrared (MWIR) wavelengths are desirable for free space communications systems because they have lower atmospheric scattering losses compared to near-infrared communication links. This leads to increased range and link uptimes. Since this portion of the EM spectrum is unlicensed, link establishment can be implemented quickly. Quantum cascade lasers (QCL) are ideal FSOC transmitters because their emission wavelength is adjustable to MWIR 3 . Compared to the typical VCSEL and laser diodes used in commercial NIR and SWIR FSOC systems, however, they require increased threshold and modulation currents 4 . Receivers based on type-II superlattice (T2SL) detectors are desired in FSOC for their low dark current, high temperature operation, and band gap tunable to MWIR 5. In this paper, we demonstrate the implementation of a high-speed FSOC system using a QCL and a T2SL detector. [reprint (PDF)]
16.	Growth of GaInAs‐InP multiquantum wells on garnet (GGG=Gd3Ga5O12) substrate by metalorganic chemical vapor deposition M. Razeghi; P‐L. Meunier; P. Maurel M. Razeghi, P‐L. Meunier, P. Maurel; Growth of GaInAs‐InP multiquantum wells on garnet (GGG=Gd3Ga5O12) substrate by metalorganic chemical vapor deposition. J. Appl. Phys. 15 March 1986; 59 (6): 2261–2263-- March 15, 1986 ...[Visit Journal] Ga0.47In0.53As‐InP multiquantum wells grown by low‐pressure metalorganic chemical vapor deposition on garnet (GGG=Gd3Ga5O12 with a=12.383 Å) substrates are presented for the first time. The x‐ray diffraction pattern shows that the orientation of the epitaxial layer is (111) while the underlying substrate orientation is (100). The photoluminescence at 77 K is due to the GaInAs layers. [reprint (PDF)]
15.	Investigations on the substrate dependence of the properties in nominally-undoped β-Ga2O3 thin films grown by PLD F. H. Teherani ; D. J. Rogers ; V. E. Sandana ; P. Bove ; C. Ton-That ; L. L. C. Lem ; E. Chikoidze ; M. Neumann-Spallart ; Y. Dumont ; T. Huynh ; M. R. Phillips ; P. Chapon ; R. McClintock ; M. Razeghi Proc. SPIE 10105, Oxide-based Materials and Devices VIII, 101051R-OLD-- March 23, 2017 ...[Visit Journal] Nominally-undoped Ga₂O₃ layers were deposited on a-, c- and r-plane sapphire substrates using pulsed laser deposition. Conventional x-ray diffraction analysis for films grown on a- and c-plane sapphire showed the layers to be in the β-Ga₂O₃ phase with preferential orientation of the (-201) axis along the growth direction. Pole figures revealed the film grown on r-plane sapphire to also be in the β-Ga₂O₃ phase but with epitaxial offsets of 29.5°, 38.5° and 64° from the growth direction for the (-201) axis. Optical transmission spectroscopy indicated that the bandgap was ~5.2eV, for all the layers and that the transparency was > 80% in the visible wavelength range. Four point collinear resistivity and Van der Pauw based Hall measurements revealed the β-Ga₂O₃ layer on r-plane sapphire to be 4 orders of magnitude more conducting than layers grown on a- and c-plane sapphire under similar conditions. The absolute values of conductivity, carrier mobility and carrier concentration for the β-Ga₂O₃ layer on r-sapphire (at 20Ω-1.cm^-1, 6 cm²/Vs and 1.7 x 10¹⁹ cm^-3, respectively) all exceeded values found in the literature for nominally-undoped β-Ga₂O₃ thin films by at least an order of magnitude. Gas discharge optical emission spectroscopy compositional depth profiling for common shallow donor impurities (Cl, F, Si and Sn) did not indicate any discernable increase in their concentrations compared to background levels in the sapphire substrate. It is proposed that the fundamentally anisotropic conductivity in β-Ga₂O₃ combined with the epitaxial offset of the (-201) axis observed for the layer grown on r-plane sapphire may explain the much larger carrier concentration, electrical conductivity and mobility compared with layers having the (-201) axis aligned along the growth direction. [reprint (PDF)]
15.	Type-II InAs/GaSb/AlSb superlatticebased heterojunction phototransistors: back to the future Abbas Haddadi, Arash Dehzangi, Romain Chevallier, Thomas Yang, Manijeh Razeghi Proc. SPIE 10540, Quantum Sensing and Nano Electronics and Photonics XV- Page-1054004-1-- January 26, 2018 ...[Visit Journal] Most of reported HPTs in literatures are based on InGaAs compounds that cover NIR spectral region. However, InGaAs compounds provide limited cut-off wavelength tunability. In contrast, type-II superlattices (T2SLs) are a developing new material system with intrinsic advantages such as great flexibility in bandgap engineering, low growth and manufacturing cost, high-uniformity, auger recombination suppression, and high carrier effective mass that are becoming an attractive candidate for infrared detection and imaging from short-wavelength infrared to very long wavelength infrared regime. We present the recent advancements in T2SL-based heterojunction phototransistors in e– SWIR, MWIR and LWIR spectral ranges. A mid-wavelength infrared heterojunction phototransistor based on type-II InAs/AlSb/GaSb superlattices on GaSb substrate has been demonstrated. Then, we present the effect of vertical scaling on the optical and electrical performance of heterojunction phototransistors, where the performance of devices with different base width was compared as the base was scaled from 60 down to 40 nm. [reprint (PDF)]
15.	Well Resolved Room Temperature Photovoltage Spectra of GaAs-GaInP Quantum Wells and Superlattices Xiaoguang He and Manijeh Razeghi Applied Physics Letters 62 (6)-- February 8, 1993 ...[Visit Journal] We report the first well resolved room‐temperature photovoltage spectra due to the sublevel transitions in the GaInP‐GaAs superlattices and multiquantum wells grown by low pressure metalorganic chemical vapor deposition. Sharp well resolved peaks attributed to exciton absorption of the electron‐to‐light hole and electron‐to‐heavy hole have been observed at room temperature. This indicates that GaAs‐GaInP is a promising material for the application of the modulators, optical switches, and optical bistable divices. Satisfactory agreements between experimental measurements and theoretical results have been obtained. These results demonstrate that photovoltage spectroscopy is a simple, but very powerful tool to study quantum confinement structures. [reprint (PDF)]
15.	High Detectivity InAs Quantum-Dot Infrared Photodetectors Grown on InP by Metalorganic Chemical Vapor Deposition W. Zhang, H. Lim, M. Taguchi, S. Tsao, B. Movaghar, and M. Razeghi Applied Physics Letters, 86 (19)-- May 9, 2005 ...[Visit Journal] We report a high-detectivity InAs quantum-dot infrared photodetector. The InAs quantum dots were grown by self-assembly on InP substrates via low-pressure metal–organic chemical–vapor deposition. Highly uniform quantum dots with a density of 4×10¹⁰ cm² were grown on a GaAs/InP matrix. Photoresponse was observed at temperatures up to 160 K with a peak of 6.4 µm and cutoff of 6.6 µm. Very low dark currents and noise currents were obtained by inserting Al_0.48In_0.52As current blocking layers. The background-limited performance temperature was 100 K. A detectivity of 1.0×10¹⁰ cm·Hz^½/W was obtained at 77 K with a bias of –1.1 V. [reprint (PDF)]

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