Center for Quantum Devices - Most Downloaded Journal Articles

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16.	Reliability of strain-balanced Ga_0.331In_0.669As/Al_0.659In_0.341As/InP quantum-cascade lasers under continuous-wave room-temperature operation A. Evans and M. Razeghi Applied Physics Letters, 88 (26)-- June 26, 2006 ...[Visit Journal] Constant current aging is reported for two randomly selected high-reflectivity-coated QCLs with an output power over 100 mW. QCLs are tested under continuous-wave operation at a heat sink temperature of 298 K(25 °C) corresponding to an internal temperature of 378 K (105 °C). Over 4000 h of continuous testing is reported without any decrease in output power. [reprint (PDF)]
16.	Background limited performance of long wavelength infrared focal plane arrays fabricated from type-II InAs/GaSb M-structure superlattice P.Y. Delaunay, B.M. Nguyen and M. Razeghi SPIE Porceedings, Vol. 7298, Orlando, FL 2009, p. 72981Q-- April 13, 2009 ...[Visit Journal] Recent advances in growth techniques, structure design and processing have lifted the performance of Type-II InAs/GaSb superlattice photodetectors. The introduction of a M-structure design improved both the dark current and R0A of Type-II photodiodes. This new structure combined with a thick absorbing region demonstrated background limited performance at 77K for a 300K background and a 2-π field of view. A focal plane array with a 9.6 μm 50% cutoff wavelength was fabricated with this design and characterized at 80K. The dark current of individual pixels was measured around 1.3 nA, 7 times lower than previous superlattice FPAs. This led to a higher dynamic range and longer integration times. The quantum efficiency of detectors without anti-reflective coating was 72%. The noise equivalent temperature difference reached 23 mK. The deposition of an anti-reflective coating improved the NEDT to 20 mK and the quantum efficiency to 89%. [reprint (PDF)]
16.	Type-II superlattice-based extended short-wavelength infrared focal plane array with an AlAsSb/GaSb superlattice etch-stop layer to allow near-visible light detection Romain Chevallier, Arash Dehzangi, Abbas Haddadi, and Manijeh Razeghi Optics Letters Vol. 42, Iss. 21, pp. 4299-4302-- October 17, 2017 ...[Visit Journal] A versatile infrared imager capable of imaging the near-visible to the extended short-wavelength infrared (e-SWIR) is demonstrated using e-SWIR InAs/GaSb/AlSb type-II superlattice-based photodiodes. A bi-layer etch-stop scheme consisting of bulk InAs_0.91Sb_0.09 and AlAs_0.1Sb_0.9/GaSb superlattice layers is introduced for substrate removal from the hybridized back-side illuminated photodetectors. The implementation of this new technique on an e-SWIR focal plane array results in a significant enhancement in the external quantum efficiency (QE) in the 1.8–0.8μm spectral region, while maintaining a high QE at wavelengths longer than 1.8μm. Test pixels exhibit 100% cutoff wavelengths of ∼2.1 and ∼2.25μm at 150 and 300K, respectively. They achieve saturated QE values of 56% and 68% at 150 and 300K, respectively, under back-side illumination and without any anti-reflection coating. At 150K, the photodetectors (27μm×27μm area) exhibit a dark current density of 4.7×10⁻⁷ A/cm² under a −50 mV applied bias providing a specific detectivity of 1.77×10¹² cm·Hz^1/2/W. At 300K, the dark current density reaches 6.6×10⁻² A/cm² under −50 mV bias, providing a specific detectivity of 5.17×10⁹ cm·Hz^1/2/W. [reprint (PDF)]
16.	High-Performance Type-II InAs/GaSb Superlattice Photodiodes with Cutoff Wavelength Around 7 µm Y. Wei, A. Hood, H. Yau, V. Yazdanpanah, M. Razeghi, M.Z. Tidrow and V. Nathan Applied Physics Letters, 86 (9)-- February 28, 2005 ...[Visit Journal] We report the most recent result in the area of type-II InAs/GaSb superlattice photodiodes that have a cutoff wavelength around 7 µm at 77 K. Superlattice with a period of 40 Å lattice matched to GaSb was realized using Ga_xIn_1–x type interface engineering technique. Compared with significantly longer period superlattices, we have reduced the dark current density under reverse bias dramatically. For a 3 µm thick structure, using sulfide-based passivation, the dark current density reached 2.6×10^–5 A/cm² at –3 V reverse bias at 77 K. At this temperature the photodiodes have R₀A of 9300 Ω·cm² and a thermally limited zero bias detectivity of 1×10¹² cm·Hz^½/W. The 90%–10% cutoff energy width was only 16.5 meV. The devices did not show significant dark current change at 77 K after three months storage in the atmosphere. [reprint (PDF)]
16.	InAsSb/InAsP strained-layer superlattice injection lasers operating at 4.0 μm grown by metal-organic chemical vapor deposition B. Lane, Z. Wu, A. Stein, J. Diaz, and M. Razeghi Applied Physics Letters 74 (23)-- June 7, 1999 ...[Visit Journal] We report high power mid-infrared electrical injection operation of laser diodes based on InAsSb/InAsP strained-layer superlattices grown on InAs substrate by metal-organic chemical vapor deposition. The broad-area laser diodes with 100 μm aperture and 1800 μm cavity length demonstrate peak output powers of 546 and 94 mW in pulsed and cw operation respectively at 100 K with a threshold current density as low as 100 A/cm². [reprint (PDF)]
16.	Low pressure metalorganic chemical vapor deposition of InP and related compounds M. Razeghi, M. A. Poisson, J. P. Larivain & J. P. Duchemin Razeghi, M., Poisson, M.A., Larivain, J.P. et al. Low pressure metalorganic chemical vapor deposition of InP and related compounds. J. Electron. Mater. 12, 371–395 (1983). https://doi.org/10.1007/BF02651138-- March 1, 1983 ...[Visit Journal] The low pressure metalorganic chemical vapor deposition epitaxial growth and characterization of InP, Ga0.47In0.53 As and GaxIn1-xAsyP1-y, lattice-matched to InP substrate are described. The layers were found to have the same etch pit density (EPD) as the substrate. The best mobility obtained for InP was 5300 cm2 V−1S−1 at 300 K and 58 900 cm2 V−1 S−1 at 772K, and for GaInAs was 11900 cm2 V−1 S−1 at 300 K, 54 600 cm2 V−1 S−1 at 77 K and 90 000 cm V−1S−1 at 2°K. We report the first successful growth of a GaInAs-InP superlattice and the enhanced mobility of a two dimensional electron gas at a GaInAs -InP heterojunction grown by LP-MO CVD. LP MO CVD material has been used for GaInAsPInP, DH lasers emitting at 1.3 um and 1.5 um. These devices exhibit a low threshold current, a slightly higher than liquid phase epitaxy devices and a high differential quantum efficiency of 60%. Fundamental transverse mode oscillation has been achieved up to a power outpout of 10 mW. Threshold currents as low as 200 mA dc have been measured for devices with a stripe width of 9 um and a cavity length of 300 um for emission at 1.5 um. Values of T in the range 64–80 C have been obtained. Preliminary life testing has been carried out at room temperature on a few laser diodes (λ = 1.5μm). Operation at constant current for severalthousand hours has been achieved with no change in the threshold current. [reprint (PDF)]
15.	Energy harvesting from millimetric ZnO single wire piezo-generators Rogers, D. J.; Carroll, C.; Bove, P.; Sandana, V. E.; Goubert, L.; Largeteau, A.; Teherani, F. Hosseini; Demazeau, G.; McClintock, R.; Drouhin, H.-J.; Razeghi, M. Oxide-based Materials and Devices III. Edited by Teherani, Ferechteh H.; Look, David C.; Rogers, David J. Proceedings of the SPIE, Volume 8263, article id. 82631X, 7 pp. (2012).-- February 9, 2013 ...[Visit Journal] This work reports on investigations into the possibility of harvesting energy from the piezoelectric response of millimetric ZnO rods to movement. SEM & PL studies of hydrothermally grown ZnO rods revealed sizes ranging from 1 - 3 mm x 100 - 400 microns and suggested that each was a wurtzite monocrystal. Studies of current & voltage responses as a function of time during bending with a probe arm gave responses coherent with those reported elsewhere in the literature for ZnO nanowires or micro-rod single wire generators. The larger scale of these rods provided some advantages over such nano- and microstructures in terms of contacting ease, signal level & robustness. [reprint (PDF)]
15.	Demonstration of a 256x256 Middle-Wavelength Infrared Focal Plane Array based on InGaAs/InGaP Quantum Dot Infrared Photodetectors (QDIPs) J. Jiang, K. Mi, S. Tsao, W. Zhang, H. Lim, T.O'Sullivan, T. Sills, M. Razeghi, G.J. Brown, and M.Z. Tidrow Applied Physics Letters, 84 (13)-- April 29, 2004 ...[Visit Journal] We report a demonstration of an infrared focal plane array based on InGaAs/InGaP quantum dot infrared photodetectors. The middle-wavelength infrared quantum-dot infrared photodetector (QDIP) structure was grown via low-pressure metal organic chemical vapor deposition. A detectivity of 3.6×10¹⁰ cm·Hz^½/W was achieved at T = 95 K and a bias of –1.4 V. The background limited temperature of our QDIP was 140 K with a 45° field of view. A 256×256 detector array was fabricated with dry etching, and hybridized to a Litton readout chip by indium bumps. Thermal imaging was achieved at temperatures up to 120 K. At T = 77 K, the noise equivalent temperature difference was measured as 0.509 K with a 300 K background and f/2.3 optics. [reprint (PDF)]
15.	Electron Transport Properties of Ga[0.51]In[0.49]P for Device Applications C. Besikci and M. Razeghi IEEE Transactions on Electron Devices 41 (6)-- June 1, 1994 ...[Visit Journal] We present Monte Carlo calculations of steady-state and transient electron transport properties of Ga0.51In0.49P. We have made a simulation-based comparison between Ga0.51In0.49P and AlxGa1-xAs (x = 0.2, 0.3). Our Monte Carlo data show that transport properties of Ga0.51In0.49P are favorable, and when the other advantages of the GaInP/GaAs system are also taken into account. this material is a good choice to replace AlxGa1-xAs (x greater-than-or-equal-to 0.3). We have also calculated electron drift and Hall mobilities in Ga0.51In0.49P as a function of impurity concentration and temperature, and determined the effects of different scattering mechanisms on the low-field mobility. Calculated results are in good agreement with the measurements on metal organic chemical vapor deposition (MOCVD) grown samples with Hall mobilities within a factor of 0.5 of the calculated theoretical limit. It has also been found that alloy scattering is an important mobility degrading mechanism in lightly doped material at low temperatures. [reprint (PDF)]
15.	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)]
15.	Gain-length scaling in quantum dot/quantum well infrared photodetectors T. Yamanaka, B. Movaghar, S. Tsao, S. Kuboya, A. Myzaferi and M. Razeghi Virtual Journal of Nanoscale Science & Technology-- September 14, 2009 ...[Visit Journal][reprint (PDF)]
15.	Injector doping level dependent continuous-wave operation of InP-based QCLs at λ~ 7.3 µm above room temperature J.S. Yu, S. Slivken, and M. Razeghi Semiconductor Science and Technology (SST), Vol. 25, No. 12, p. 125015-- December 1, 2010 ...[Visit Journal] We report the continuous-wave (CW) operation of InGaAs/InAlAs quantum cascade lasers (QCLs) operating at λ ~ 7.3 µm above room temperature. The injector doping level–dependent CW characteristics above room temperature are investigated for doping densities between 7 × 10¹⁶ cm⁻³ and 2 × 10¹⁷ cm⁻³. The device performance, i.e. threshold current density, output power, operating temperature and characteristic temperature, depends strongly on the injector doping density. For a relatively low injector doping density of 7 × 10¹⁶ cm⁻³, a high-reflectivity-coated 10 µm wide and 4 mm long laser exhibits an improved device performance with an output power of 152 mW and a threshold current density of 1.37 kA cm⁻² at 298 K under CW mode, operating up to 343 K. The thermal characteristics are also analyzed by the estimation from the experimentally measured data for the QCLs with different injector doping densities. [reprint (PDF)]
15.	Characterization of InTlSb/InSb Grown by Low Pressure Metalorganic Chemical Vapor Deposition on GaAs Substrat Y.H. Choi, P. Staveteig, E. Bigan, and M. Razeghi Journal of Applied Physics 75 (6)-- March 15, 1994 ...[Visit Journal] Optical properties of InTlSb, a new long wavelength infrared material, are investigated. InTlSb/InSb epilayers grown by low‐pressure metal‐organic chemical vapor deposition on semi‐insulating GaAs substrates were characterized using Auger electron spectroscopy and Fourier transform infrared spectroscopy. Auger electron spectra confirm the presence of thallium. Transmission measurements at 77 K indicate an absorption shift from 5.5 μm for InSb up to 8 μm for InTlSb that is confirmed by photoconductivity measurements. [reprint (PDF)]
15.	Solar-blind photodetectors based on Ga₂O₃ and III-nitrides Ryan McClintock; Alexandre Jaud; Lakshay Gautam; Manijeh Razeghi Proc. SPIE 11288, Quantum Sensing and Nano Electronics and Photonics XVII, 1128803-- January 31, 2020 ...[Visit Journal] Recently, there has been a surge of interest in the wide bandgap semiconductors for solar blind photo detectors (SBPD). This work presents our recent progress in the growth/doping of AlGaN and Ga₂O₃ thin films for solar blind detection applications. Both of these thin films grown are grown by metal organic chemical vapor deposition (MOCVD) in the same Aixtron MOCVD system. Solar-blind metal-semiconductor-metal photodetectors were fabricated with Ga₂O₃. Spectral responsivity studies of the MSM photodetectors revealed a peak at 261 nm and a maximum EQE of 41.7% for a −2.5 V bias. We have also demonstrated AlGaN based solar-blind avalanche photodiodes with a gain in excess of 57,000 at ~100 volts of reverse bias. This gain can be attributed to avalanche multiplication of the photogenerated carriers within the device. Both of these devices show the potential of wide bandgap semiconductors for solar blind photo detectors. [reprint (PDF)]
15.	High‐quality GaAs/Ga0.49In0.51P superlattices grown on GaAs and silicon substrates by low‐pressure metalorganic chemical vapor deposition Available M. Razeghi; Ph. Maurel; F. Omnes; M. Defour; C. Boothroyd; W. M. Stobbs; M. Kelly J. Appl. Phys. 63, 4511–4514 (1988) -- May 1, 1988 ...[Visit Journal] We report the successful growth of Ga0.49 Iuo.5 ! P-GaAs superlattices on GaAs and Si substrates by low-pressure metalorganic chemical vapor deposition. The high quality of the structure grown on GaAs and silicon substrates has been evidenced by transmission electron microscopy photographs, that show very sharp interfaces between GaAs wells and Gao.49InO.51 P barriers, with perfect control of thicknesses and compositions. Classical Hall measurements performed on the sample further demonstrated the presence of a twodimensional electron ga.<; with a mobility at T = 4 K , fL (4 K) = 50000 cm2 1V Is, and a carrier concentration n _ (4 K) = 2,9 X 1011 em -2. GaAs/Gao.49 InO. 51 P superlattices have been used, as well as buffer layer in order to grow GaAs on silicon substrates. Mirrorlike single-crystal GaAs has thus been obtained. A GaInP IGaAs heterostructure with electron HaH mobility as high as 6000 cm2 /V Is at 300 K and 80000 cm2 /V Is at 4 K has been grown, which is the highest mobility that has yet been reported for these materials, [reprint (PDF)]
15.	Performance characteristics of high-purity mid-wave and long-wave infrared type-II InAs/GaSb superlattice infrared photodiodes A. Hood, M. Razeghi, V. Nathan and M.Z. Tidrow SPIE Conference, San Jose, CA, Vol. 6127, pp. 61270U-- January 23, 2006 ...[Visit Journal] The authors report on recent advances in the development of mid-, long-, and very long-wavelength infrared (MWIR, LWIR, and VLWIR) Type-II InAs/GaSb superlattice infrared photodiodes. The residual carrier background of binary Type-II InAs/GaSb superlattice photodiodes of cut-off wavelengths around 5 µm has been studied in the temperature range between 10 and 200 K. A four-point, capacitance-voltage technique on mid-wavelength and long-wavelength Type-II InAs/GaSb superlattice infrared photodiodes reveal residual background concentrations around 5×10¹⁴ cm^-3. Additionally, recent progress towards LWIR photodiodes for focal plane array imaging applications is presented. [reprint (PDF)]
15.	High performance LWIR Type-II InAs/GaSb superlattice photodetectors and infrared focal plane array Y. Wei, A. Hood, A. Gin, V. Yazdanpanah, M. Razeghi and M. Tidrow SPIE Conference, Jose, CA, Vol. 5732, pp. 309-- January 22, 2005 ...[Visit Journal] We report on the demonstration of a focal plane array based on Type-II InAs-GaSb superlattices grown on n-type GaSb substrate with a 50% cutoff wavelength at 10 μm. The surface leakage occurring after flip-chip bonding and underfill in the Type-II devices was suppressed using a double heterostructure design. The R₀A of diodes passivated with SiO₂ was 23 Ω·cm² after underfill. A focal plane array hybridized to an Indigo readout integrated circuit demonstrated a noise equivalent temperature difference of 33 mK at 81 K, with an integration time of 0.23 ms. [reprint (PDF)]
15.	Widely tuned room temperature terahertz quantum cascade laser sources Q.Y. Lu, N. Bandyopadhyay, S. Slivken, Y. Bai and M. Razeghi SPIE Proceedings, Vol. 8631, p. 863108-1, Photonics West, San Francisco, CA-- February 3, 2013 ...[Visit Journal] Room temperature THz quantum cascade laser sources with a broad spectral coverage based on intracavity difference frequency generation are demonstrated. Two mid-infrared active cores in the longer mid-IR wavelength range (9-11 micron)based on the single-phonon resonance scheme are designed with a second-order difference frequency nonlinearity specially optimized for the high operating fields that correspond to the highest mid-infrared output powers. A Čerenkov phase-matching scheme along with integrated dual-period distributed feedback gratings are used for efficient THz extraction and spectral purification. Single mode emissions from 1.0 to 4.6 THz with a side-mode suppression ratio and output power up to 40 dB and 32 μW are obtained, respectively. [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.	High-Performance InP-Based Mid-IR Quantum Cascade Lasers M. Razeghi IEEE Journal of Selected Topics in Quantum Electronics, Vol. 15, No. 3, May-June 2009, p. 941-951.-- June 5, 2009 ...[Visit Journal] Quantum cascade lasers (QCLs) were once considered as inefficient devices, as the wall-plug efficiency (WPE) was merely a few percent at room temperature. But this situation has changed in the past few years, as dramatic enhancements to the output power andWPE have been made for InP-based mid-IR QCLs. Room temperature continuous-wave (CW) output power as high as 2.8 W and WPE as high as 15% have now been demonstrated for individual devices. Along with the fundamental exploration of refining the design and improving the material quality, a consistent determination of important device performance parameters allows for strategically addressing each component that can be improved potentially. In this paper, we present quantitative experimental evidence backing up the strategies we have adopted to improve the WPE for QCLs with room temperature CW operation. [reprint (PDF)]
15.	Ga/sub 0.51/In/sub 0.49/P/GaAs HEMT's exhibiting good electrical performance at cryogenic temperatures Y.-J. Chan; D. Pavlidis; M. Razeghi; F. Omnes IEEE TRANS. ELEC.DEVICES. 77. IO. 1990-- October 1, 1990 ...[Visit Journal] The DC and microwave characteristics of Ga/sub 0.51/In/sub 0.49/P/GaAs HEMTs grown by metalorganic chemical vapor deposition (MOCVD) are presented. Devices with 1- mu m-long gates show transconductances of 163 and 213 mS/mm at 300 and 77 K, respectively. Their maximum cutoff frequency is 17.8 GHz. Deep traps in the doped layer are evaluated at low temperature by the threshold voltage shift and current collapse phenomena. GaInP/GaAs HEMTs show no current collapse and have almost zero threshold voltage shift compared to AlGaAs/GaAs and InAlAs/InGaAs where the corresponding values are 0.5 and 0.25 V, respectively. [reprint (PDF)]
15.	Background limited long wavelength infrared type-II InAs/GaSb superlattice photodiodes operating at 110 K B.M. Nguyen, D. Hoffman, E.K. Huang, P.Y. Delaunay, and M. Razeghi Applied Physics Letters, Vol. 93, No. 12, p. 123502-1-- September 22, 2008 ...[Visit Journal] The utilization of the P+-pi-M-N+ photodiode architecture in conjunction with a thick active region can significantly improve long wavelength infrared Type-II InAs/GaSb superlattice photodiodes. By studying the effect of the depletion region placement on the quantum efficiency in a thick structure, we achieved a topside illuminated quantum efficiency of 50% for an N-on-P diode at 8.0 µm at 77 K. Both the double heterostructure design and the application of polyimide passivation greatly reduce the surface leakage, giving an R₀A of 416 Ω·cm² for a 1% cutoff wavelength of 10.52 µm, a Shot–Johnson detectivity of 8.1×10¹¹ cm·Hz^½/W at 77 K, and a background limited operating temperature of 110 K with 300 K background. [reprint (PDF)]
15.	Gain and recombination dynamics of quantum-dot infrared photodetecto H. Lim, B. Movaghar, S. Tsao, M. Taguchi, W. Zhang, A.A. Quivy, and M. Razeghi Virtual Journal of Nanoscale Science & Technology-- December 4, 2006 ...[Visit Journal][reprint (PDF)]
15.	Passivation of Type-II InAs/GaSb superlattice photodetectors A. Hood, Y. Wei, A. Gin, M. Razeghi, M. Tidrow, and V. Nathan SPIE Conference, Jose, CA, Vol. 5732, pp. 316-- January 22, 2005 ...[Visit Journal] Leakage currents limit the operation of high performance Type-II InAs/GaSb superlattice photodiode technology. Surface leakage current becomes a dominant limiting factor, especially at the scale of a focal plane array pixel (< 25 µm) and must be addressed. A reduction of the surface state density, unpinning the Fermi level at the surface, and appropriate termination of the semiconductor crystal are all aims of effective passivation. Recent work in the passivation of Type-II InAs\GaSb superlattice photodetectors with aqueous sulfur-based solutions has resulted in increased R₀A products and reduced dark current densities by reducing the surface trap density. Additionally, photoluminescence of similarly passivated Type-II InAs/GaSb superlattice and InAs GaSb bulk material will be discussed. [reprint (PDF)]
15.	Radiometric characterization of long-wavelength infrared type II strained layer superlattice focal plane array under low-photon irradiance conditions J. Hubbs, V. Nathan, M. Tidrow, and M. Razeghi Optical Engineering, Vol. 51, No. 6, p. 064002-1-- June 15, 2012 ...[Visit Journal] We present the results of the radiometric characterization of an “M” structure long wavelength infrared Type-II strained layer superlattice(SLS) infrared focal plane array (IRFPA) developed by Northwestern University (NWU). The performance of the M-structure SLS IRFPA was radiometrically characterized as a function of photon irradiance, integration time, operating temperature, and detector bias. Its performance is described using standard figures of merit: responsivity, noise, and noise equivalent irradiance. Assuming background limited performance operation at higher irradiances, the detector quantum efficiency for the SLS detector array is approximately 57%. The detector dark density at 80 K is 142 μA∕cm², which represents a factor of seven reduction from previously measured devices. [reprint (PDF)]

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