Center for Quantum Devices - Most Downloaded Journal Articles

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4.	Semiconductor ultraviolet detectors M. Razeghi and A. Rogalski SPIE Photonics West '96 Photodetectors: Materials and Devices; Proceedings 2685-- January 27, 1996 ...[Visit Journal] This paper presents an overview of semiconductor ultraviolet (UV) detectors that are currently available and associated technologies that are undergoing further development. At the beginning, the classification of UV detectors and general requirements imposed on these detectors are presented. Further consideration are restricted to modern semiconductor UV detectors, so the current state-of-the-art of different types of semiconductor UV detectors is presented. Hitherto, the semiconductor UV detectors have been mainly fabricated using Si. Industries such as the aerospace, automotive, petroleum, and others have continuously provided the impetus pushing the development of fringe technologies which are tolerant of increasingly high temperatures and hostile environments. As a result, the main effort are currently directed to a new generation of UV detectors fabricated from wide-band-gap semiconductors between them the most promising are diamond and AlGaN. The latest progress in development of AlGaN UV detectors is finally described in detail. [reprint (PDF)]
4.	Mid-wavelength infrared high operating temperature pBn photodetectors based on type-II InAs/InAsSb superlattice Donghai Wu, Jiakai Li, Arash Dehzangi, and Manijeh Razeghi AIP Advances 10, 025018-- February 11, 2020 ...[Visit Journal] A high operating temperature mid-wavelength infrared pBn photodetector based on the type-II InAs/InAsSb superlattice on a GaSb substrate has been demonstrated. At 150 K, the photodetector exhibits a peak responsivity of 1.48 A/W, corresponding to a quantum efficiency of 47% at −50 mV applied bias under front-side illumination, with a 50% cutoff wavelength of 4.4 μm. With an R×A of 12,783 Ω·cm² and a dark current density of 1.16×10⁻⁵A/cm² under −50 mV applied bias, the photodetector exhibits a specific detectivity of 7.1×10¹¹ cm·Hz^½/W. At 300 K, the photodetector exhibits a dark current density of 0.44 A/cm²and a quantum efficiency of 39%, resultingin a specific detectivity of 2.5×10⁹ cm·Hz^½/W. [reprint (PDF)]
4.	Room temperature continuous wave operation of quantum cascade lasers with 12.5% wall plug efficiency Y. Bai, S. Slivken, S.R. Darvish, and M. Razeghi Applied Physics Letters, Vol. 93, No. 2, p. 021103-1-- July 14, 2008 ...[Visit Journal] An InP based quantum cascade laser heterostructure emitting at 4.6 µm was grown with gas-source molecular beam epitaxy. The wafer was processed into a conventional double-channel ridge waveguide geometry with ridge widths of 19.7 and 10.6 µm without semi-insulating InP regrowth. An uncoated, narrow ridge device with a 4.8 mm cavity length was epilayer down bonded to a diamond submount and exhibits 2.5 W maximum output power with a wall plug efficiency of 12.5% at room temperature in continuous wave operation. [reprint (PDF)]
4.	Very Long Wavelength GaAs/GaInP Quantum Well Infrared Photodetectors C. Jelen, S. Slivken, G.J. Brown, and M. Razeghi SPIE Conference, San Jose, CA, -- February 12, 1997 ...[Visit Journal] We demonstrate long wavelength quantum well infrared photodetectors with GaAs quantum wells and GaInP barriers grown using gas-source molecular beam epitaxy. Wafers were grown with varying well widths. The optimum well width was 75 angstrom, which resulted in a detection peak at 13 μm and a cutoff wavelength of 15 μm. Dark current measurements of the samples with 15 μm cutoff wavelength show low dark current densities. The dark current characteristics have been investigated as a function of temperature and electron density in the well and compared to a model which takes into account thermionic emission and thermally assisted tunneling. The model is used to extract a saturation velocity of 1.5 x 10⁵ cm/s for electrons. The photoelectron lifetime before recapture has been deduced from this carrier velocity and photoconductive gain measurements. The lifetime is found to be approximately 5 ps. Preliminary focal plane array imaging is demonstrated. [reprint (PDF)]
4.	Deep ultraviolet (254 nm) focal plane array E. Cicek, Z. Vashaei, R. McClintock, and M. Razeghi SPIE Proceedings, Conference on Infrared Sensors, Devices and Applications; and Single Photon Imaging II, Vol. 8155, p. 81551O-1-- August 21, 2011 ...[Visit Journal] We report the synthesis, fabrication and testing of a 320 × 256 focal plane array (FPA) of back-illuminated, solarblind, p-i-n, Al_xGa_1-xN-based detectors, fully realized within our research laboratory. We implemented a novel pulsed atomic layer deposition technique for the metalorganic chemical vapor deposition (MOCVD) growth of crackfree, thick, and high Al composition Al_xGa_1-xN layers. Following the growth, the wafer was processed into a 320 × 256 array of 25 μm × 25 μm pixels on a 30 μm pixel-pitch and surrounding mini-arrays. A diagnostic mini-array was hybridized to a silicon fan-out chip to allow the study of electrical and optical characteristics of discrete pixels of the FPA. At a reverse bias of 1 V, an average photodetector exhibited a low dark current density of 1.12×10^-8 A·cm^-2. Solar-blind operation is observed throughout the array with peak detection occurring at wavelengths of 256 nm and lower and falling off three orders of magnitude by 285 nm. After indium bump deposition and dicing, the FPA is hybridized to a matching ISC 9809 readout integrated circuit (ROIC). By developing a novel masking technology, we significantly reduced the visible response of the ROIC and thus the need for external filtering to achieve solar- and visible-blind operation is eliminated. This allowed the FPA to achieve high external quantum efficiency (EQE): at 254 nm, average pixels showed unbiased peak responsivity of 75 mA/W, which corresponds to an EQE of ~37%. Finally, the uniformity of the FPA and imaging properties are investigated. [reprint (PDF)]
4.	Modeling the electronic band-structure of strained long-wavelength Type-II superlattices using the scattering matrix method Abbas Haddadi，Gail Brown，Manijeh Razeghi Abbas Haddadi,Brown Gail and Razeghi Manijeh.Modeling the electronic band-structure of strained long-wavelength Type-II superlattices using the scattering matrix method[J].Journal of Infrared and Millimeter Waves,2025,44(3):345~350 ...[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
3.	Suppression of surface leakage in gate controlled type-II InAs/GaSb mid-infrared photodetectors G. Chen; B.-M. Nguyen; A.M. Hoang; E.K. Huang; S.R. Darvish; M. Razeghi Proc. SPIE 8268, Quantum Sensing and Nanophotonic Devices IX, 826811 (January 20, 2012)-- January 20, 2012 ...[Visit Journal] One of the biggest challenges of improving the electrical performance in Type II InAs/GaSb superlattice photodetector is suppressing the surface leakage. Surface leakage screens important bulk dark current mechanisms, and brings difficulty and uncertainty to the material optimization and bulk intrinsic parameters extraction such as carrier lifetime and mobility. Most of surface treatments were attempted beyond the mid-infrared (MWIR) regime because compared to the bulk performance, surface leakage in MWIR was generally considered to be a minor factor. In this work, we show that below 150K, surface leakage still strongly affects the electrical performance of the very high bulk performance p-π-M-n MWIR photon detectors. With gating technique, we can effectively eliminate the surface leakage in a controllable manner. At 110K, the dark current density of a 4.7 μm cut-off gated photon diode is more than 2 orders of magnitude lower than the current density in SiO₂ passivated ungated diode. With a quantum efficiency of 48%, the specific detecivity of gated diodes attains 2.5 x 10¹⁴ cm·Hz^1/2/W, which is 3.6 times higher than that of ungated diodes. [reprint (PDF)]
3.	Growth of In_1-xTl_xSb, a New Infrared Material, by Low-Pressure Metalorganic Chemical Vapor Deposition Y.H. Choi, R. Sudharsanan, C, Besikci, and M. Razeghi Applied Physics Letters 63 (3)-- July 19, 1993 ...[Visit Journal] We report the growth of In_1-xTl_xSb, a new III-V alloy for long-wavelength infrared detector applications, by low-pressure metalorganic chemical vapor deposition. In_1-xTl_xSb with good surface morphology was obtained on both GaAs and InSb substrates at a growth temperature of 455 °C. X-ray diffraction measurements showed resolved peaks of In_1-xTl_xSb and InSb films. Infrared absorption spectrum of In_1-xTl_xSb showed a shift toward lower energies compared to InSb spectrum. Hall mobility data on In_1-xTl_xSb/InSb/GaAs structure showed enhanced mobility at low temperatures compared to InSb/GaAs structure. [reprint (PDF)]
3.	Type–II superlattices base visible/extended short–wavelength infrared photodetectors with a bandstructure–engineered photo–generated carrier extractor Arash Dehzangi, Ryan McClintock, Abbas Haddadi, Donghai Wu, Romain Chevallier, Manijeh Razeghi Scientific Reports volume 9, Article number: 5003 -- March 21, 2019 ...[Visit Journal] Visible/extended short–wavelength infrared photodetectors with a bandstructure–engineered photo–generated carrier extractor based on type–II InAs/AlSb/GaSb superlattices have been demonstrated. The photodetectors are designed to have a 100% cut-off wavelength of ~2.4 μm at 300K, with sensitivity down to visible wavelengths. The photodetectors exhibit room–temperature (300K) peak responsivity of 0.6 A/W at ~1.7 μm, corresponding to a quantum efficiency of 43% at zero bias under front–side illumination, without any anti–reflection coating where the visible cut−on wavelength of the devices is <0.5 µm. With a dark current density of 5.3 × 10⁻⁴ A/cm² under −20 mV applied bias at 300K, the photodetectors exhibit a specific detectivity of 4.72 × 10¹⁰ cm·Hz^½W^-1. At 150K, the photodetectors exhibit a dark current density of 1.8 × 10⁻¹⁰ A/cm² and a quantum efficiency of 40%, resulting in a detectivity of 5.56 × 10¹³ cm·Hz^½/W [reprint (PDF)]
3.	Growth and Optimization of GaInAsP/InP Material System for Quantum Well Infrared Photodetector Applications M. Erdtmann, J. Jiang, A. Matlis, A. Tahraoui, C. Jelen, M. Razeghi, and G. Brown SPIE Conference, San Jose, CA, -- January 26, 2000 ...[Visit Journal] Multi-quantum well structures of Ga_xIn_1-xAs_yP_1-y were grown by metalorganic chemical vapor deposition for the fabrication of quantum well IR photodetectors. The thickness and composition of the wells was determined by high-resolution x-ray diffraction and photoluminescence experiments. The intersubband absorption spectrum of the Ga_0.47In_0.53As/InP, Ga_0.38In_0.62As_0.80P_0.20 (1.55 μm)/InP, and Ga_0.27In_0.73As_0.57P_0.43 (1.3 μm))/InP quantum wells are found to have cutoff wavelengths of 9.3 μm, 10.7 micrometers , and 14.2 μm respectively. These wavelengths are consistent with a conduction band offset to bandgap ratio of approximately 0.32. Facet coupled illumination responsivity and detectivity are reported for each composition. [reprint (PDF)]
3.	Thermal analysis of buried heterostructure quantum cascade lasers for long-wavelength infrared emission using 2D anisotropic heat-dissipation model H.K. Lee, K.S. Chung, J.S. Yu and M. Razeghi Physica Status Solidi (a), Vol. 206, p. 356-362-- February 1, 2009 ...[Visit Journal] We have theoretically investigated and compared the thermal characteristics of 10.6 μm InGaAs/InAlAs/InP buried heterostructure (BH) quantum cascade lasers (QCLs) with different heat-sinking configurations by a steady-state heat-transfer analysis. The heat-source densities were obtained from laser threshold power densities measured experimentally under room-temperature continuous-wave mode. The two-dimensional anisotropic heat-dissipation model was used to calculate the temperature distribution, heat flux, and thermal conductance (Gth) inside the device. For good thermal characteristics, the QCLs in the long-wavelength infrared region require the relatively narrow BH structure in combination with epilayer-down bonding due to thick active core/cladding layers and high insulator losses. The single-ridge BH structure results in slightly higher thermal conductance by 2-4% than the double-channel (DC) ridge BH structure. For W = 12 m with 5 μm thick electroplated Au, the single-ridge BH laser with epilayer-down bonding exhibited the highest G_th value of 201.9 W/K cm², i.e. increased by nearly 36% with respect to the epilayer-up bonded DC ridge waveguide laser. This value is improved by 50% and 62% with respect to the single-ridge BH laser and DC ridge waveguide laser with W = 20 μm in the epilayer-up bonding scheme, respectively. [reprint (PDF)]
3.	Angled cavity broad area quantum cascade lasers Y. Bai, S. Slivken, Q.Y. Lu, N. Bandyopadhyay, and M. Razeghi Applied Physics Letters, Vol. 100, Np. 8, p. 081106-1-- August 20, 2012 ...[Visit Journal] Angled cavity broad area quantum cascade lasers (QCLs) are investigated with surface gratingbased distributed feedback (DFB) mechanisms. It is found that an angled cavity incorporating a one dimensional DFB with grating lines parallel to the laser facet offers the simplest solution for single mode and diffraction limited emission in the facet normal direction. A room temperature single mode QCL with the highest output power for wavelengths longer than 10 micron is demonstrated. This structure could be applied to a wide range of laser structures for power scaling along with spectral and spatial beam control. [reprint (PDF)]
3.	High-power InGaAsP/GaAs 0.8 μm laser diodes and peculiarities of operational characteristics J. Diaz, I. Eliashevich, X. He, H. Yi, L. Wang, E. Kolev, D. Garbuzov, and M. Razeghi Applied Physics Letters 65 (8)-- August 22, 1994 ...[Visit Journal] High-power operation of 3 W in pulse mode, 750 mW in quasi-continuous wave and 650 mW in continuous wave per uncoated facet from 100 μm aperture has been demonstrated for 1 mm long cavity InGaAsP/GaAs 808 nm laser diodes prepared by low-pressure metalorganic chemical vapor deposition. Threshold current density of 300 A/cm², differential efficiency of 1.1 W/A, T₀=155 °C, transverse beam divergence of 27°, and less than 2 nm linewidth at 808 nm have been measured. No degradation has been observed after 1000 h of operation in a quasi-continuous wave regime. [reprint (PDF)]
3.	InAs/InAs_1-xSb_x type-II superlattices for high performance long wavelength infrared detection A. Haddadi , G. Chen , R. Chevallier , A. M. Hoang , and M. Razeghi Appl. Phys. Lett. 105, 121104 (2014)-- September 22, 2014 ...[Visit Journal] High performance long-wavelength infrared nBn photodetectors based on InAs/InAs_1−xSb_x type-II superlattices on GaSb substrate have been demonstrated. The photodetector's 50% cut-off wavelength was ∼10 μm at 77 K. The photodetector with a 6 μm-thick absorption region exhibited a peak responsivity of 4.47 A/W at 7.9 μm, corresponding to a quantum efficiency of 54% at −90 mV bias voltage under front-side illumination and without any anti-reflection coating. With an R × A of 119 Ω·cm² and a dark current density of 4.4 × 10⁻⁴ A/cm² under −90 mV applied bias at 77 K, the photodetector exhibited a specific detectivity of 2.8 × 10¹¹ cm·Hz^1/2·W^-1. [reprint (PDF)]
3.	Recent Advances in InAs/GaSb Superlattices for Very Long Wavelength Infrared Detection G.J. Brown, F. Szmulowicz, K. Mahalingam, S. Houston, Y. Wei, A. Gin and M. Razeghi SPIE Conference, San Jose, CA, Vol. 4999, pp. 457-- January 27, 2003 ...[Visit Journal] New infrared (IR) detector materials with high sensitivity, multi-spectral capability, improved uniformity and lower manufacturing costs are required for numerous long and very long wavelength infrared imaging applications. One materials system has shown great theoretical and, more recently, experimental promise for these applications: InAs/In_xGa_1-xSb type-II superlattices. In the past few years, excellent results have been obtained on photoconductive and photodiode samples designed for infrared detection beyond 15 microns. The infrared properties of various compositions and designs of these type-II superlattices have been studied. The infrared photoresponse spectra are combined with quantum mechanical modeling of predicted absorption spectra to provide insight into the underlying physics behind the quantum sensing in these materials. Results for superlattice photodiodes with cut-off wavelengths as long as 25 microns are presented. [reprint (PDF)]
3.	Recent Advances in LWIR Type-II InAs/GaSb Superlattice Photodetectors and Focal Plane Arrays at the Center for Quantum Devices M. Razeghi, D. Hoffman, B.M. Nguyen, P.Y. Delaunay, E.K. Huang, M.Z. Tidrow, and V. Nathan IEEE Proceedings, Vol. 97, No. 6, p. 1056-1066-- June 1, 2009 ...[Visit Journal] In recent years, Type-II InAs/GaSb superlattice photo-detectors have experienced significant improvements in material quality, structural designs, and imaging applications. They now appear to be a possible alternative to the state-of-the-art HgCdTe (MCT) technology in the long and very long wavelength infrared regimes. At the Center for Quantum Devices, we have successfully realized very high quantum efficiency, very high dynamic differential resistance R₀A - product LWIR Type – II InAs/GaSb superlattice photodiodes with efficient surface passivation techniques. The demonstration of high quality LWIR Focal Plane Arrays that were 100 % fabricated in - house reaffirms the pioneer position of this university-based laboratory. [reprint (PDF)]
3.	High Detectivity InGaAs/InGaP Quantum-Dot Infrared Photodetectors Grown by Low Pressure Metalorganic Chemical Vapor Deposition J. Jiang, S. Tsao, T. O'Sullivan, W. Zhang, H. Lim, T. Sills, K. Mi, M. Razeghi, G.J. Brown, and M.Z. Tidrow Virtual Journal of Nanoscale Science and Technology 9 (12)-- March 29, 2004 ...[Visit Journal][reprint (PDF)]
3.	High-speed short wavelength infrared heterojunction phototransistors based on type II superlattices Jiakai Li; Arash Dehzangi; Donghai Wu; Manijeh Razeghi Proc. SPIE 11288, Quantum Sensing and Nano Electronics and Photonics XVII, 1128813-- January 31, 2020 ...[Visit Journal] A two terminal short wavelength infrared heterojunction phototransistors based on type-II InAs/AlSb/GaSb on GaSb substrate are designed fabricated and presented. With the base thickness of 40 nm, the device exhibited 100% cut-off wavelengths of ~2.3 μm at 300K. The saturated peak responsivity value is of 325.5 A/W at 300K, under front-side illumination without any anti-reflection coating. A saturated optical gain at 300K was 215 a saturated dark current shot noise limited specific detectivity of 4.9×10¹¹ cm·Hz^½/W at 300 K was measured. Similar heterojunction phototransistor structure was grown and fabricated with different method of processing for high speed testing. For 80 μm diameter circular diode size under 20 V applied reverse bias, a −3 dB cut-off frequency of 1.0 GHz was achieved, which showed the potential of type-II superlattice based heterojunction phototransistors to be used for high speed detection. [reprint (PDF)]
3.	Ultraviolet Detectors for AstroPhysics Present and Future M. Ulmer, M. Razeghi, and E. Bigan Optoelectronic Integrated Circuit Materials, Physics and Devices, SPIE Conference, San Jose, CA; Proceedings, Vol. 239-- February 6, 1995 ...[Visit Journal] Astronomical instruments for the study of UV astronomy have been developed for NASA missions such as the Hubble Space Telescope. The systems that are `blind to the visible' (`solar-blind') yet sensitive to the UV that have been flown in satellites have detective efficiencies of about 10 to 20%, although typically electron bombardment charge coupled devices are higher at 30 - 40% and ordinary CCDs achieve 1 - 5%. Therefore, there is a large payoff still to be gained by further improvements in the performance of solar blind UV detectors. We provide a brief review of some aspects of UV astronomy, UV detector development, and possible technologies for the future. We suggest that a particularly promising future technology is one based on the ability of investigators to produce high quality films made of wide bandgap III-V semiconductors. [reprint (PDF)]
3.	Theoretical investigation of minority carrier leakage of high-power 0.8 μm InGaAsP/InGaP/GaAs laser diodes J. Diaz, I. Eliashevich, H.J. Yi, M. Stanton, and M. Razeghi Applied Physics Letters 65 (18)-- October 31, 1994 ...[Visit Journal] We report a theoretical model that accurately describes the effects of minority carrier leakage from the InGaAsP waveguide into InGaP cladding layers in high‐power aluminum-free 0.8 μm InGaAsP/InGaP/GaAs separate confinement heterostructure lasers. Current leakage due to the relatively low band‐gap discontinuity between the active region and the InGaP barrier can be eliminated by employing laser diodes with cavity length longer than 500 μm. Experimental results for lasers grown by low-pressure metalorganic chemical vapor deposition are in excellent agreement with the theoretical model. [reprint (PDF)]
3.	Neutron Activation Analysis of an Iranian Cigarette and its Smoke Z. Abedinzadeh, M. Razeghi and B. Parsa Z. Abedinzadeh, M. Razeghi and B. Parsa, Journal of Radioanalytical Chemistry, VoL 35 [1977) 373-376-- September 1, 1977 ...[Visit Journal] Non-destructive neutron activation analysis, employing a high-resolution Ge(Li) detector, was applied to determine the concentration of 24 trace elements in the tobacco of the Zarrin cigarette which is commercially made in Iran. These elements are: Na, K, Sc, Cr, Mn, Fe, Co, Zn, Se, Br, Rb, Ag, Sb, Cs, Ba, La, Ce, Sm, Eu, Tb, Hf, Au, Hg and Th. The smokes from the combustion of this tobacco and of the cigarette paper were also analysed for these elements and the percentage transference values were calculated. [reprint (PDF)]
3.	Recent advances in IR semiconductor laser diodes and future trends M. Razeghi; Y. Bai; N. Bandyopadhyay; B. Gokden; Q.Y. Lu; S. Slivken Photonics Society Summer Topical Meeting Series, IEEE [6000041], pp. 55-56 (2011)-- July 18, 2011 ...[Visit Journal] The wall plug efficiency of the mid-infrared quantum cascade laser in room temperature continuous wave (cw) operation is brought to 21%, with a maximum output power of 5.1 W. Using a surface grating distributed feedback (DFB) approach, we demonstrated 2.4 W single mode output in room temperature cw operation. With a photonic crystal distributed feedback (PCDFB) design, we achieved single mode spectrum and close to diffraction limited far field with a room temperature high peak power of 34 W. [reprint (PDF)]
3.	High speed type-II superlattice based photodetectors transferred on sapphire Arash Dehzangi, Ryan McClintock, Donghai Wu, Jiakai Li, Stephen Johnson, Emily Dial and Manijeh Razeghi Applied Physics Express, Volume 12, Number 11-- October 3, 2019 ...[Visit Journal] We report the substrate transfer of InAs/GaSb/AlSb based type-II superlattice (T2SL) e-SWIR photodetector from native GaSb substrates to low loss sapphire substrate in order to enhance the frequency response of the device. We have demonstrated the damage-free transfer of T2SL-based thin-films to sapphire substrate using top–down processing and a chemical epilayer release technique. After transfer the −3 dB cut-off frequency increased from 6.4 GHz to 17.2 GHz, for 8 μm diameter circular mesas under -15 V applied bias. We also investigated the cut-off frequency verses applied bias and lateral scaling to assess the limitations for even higher frequency performance. Direct Link [reprint (PDF)]
3.	Demonstration of type-II superlattice MWIR minority carrier unipolar imager for high operation temperature application Guanxi Chen, Abbas Haddadi, Anh-Minh Hoang, Romain Chevallier, and Manijeh Razeghi Optics Letters Vol. 40, Iss. 1, pp. 29–32-- December 18, 2014 ...[Visit Journal] An InAs/GaSb type-II superlattice-based mid-wavelength infrared (MWIR) 320×256 unipolar focal plane array (FPA) using pMp architecture exhibited excellent infrared image from 81 to 150 K and ∼98% operability, which illustrated the possibility for high operation temperature application. At 150 K and −50 mV operation bias, the 27 μm pixels exhibited dark current density to be 1.2×10⁻⁵ A/cm², with 50% cutoff wavelength of 4.9 μm, quantum efficiency of 67% at peak responsivity (4.6 μm), and specific detectivity of 1.2×10¹² Jones. At 90 K and below, the 27 μm pixels exhibited system limited dark current density, which is below 1×10⁻⁹ A/cm², and specific detectivity of 1.5×10¹⁴ Jones. From 81 to 100 K, the FPA showed ∼11 mK NEDT by using F/2.3 optics and a 9.69 ms integration time. [reprint (PDF)]
3.	Quantum Dot Intersubband Photodetectors C. Jelen, M. Erdtmann, S. Kim, and M. Razeghi SPIE Conference, San Jose, CA, -- January 22, 2001 ...[Visit Journal] Quantum dots are recognized as very promising candidates for the fabrication of intersubband photodetectors in the infrared spectral range. At present, material quality is making rapid progress and some devices have been demonstrated. Examples of mid-infrared quantum dot intersubband photodetectors are presented along with device design and data analysis. Nonetheless, the performance of these devices remains less than comparable quantum well intersubband photodetectors due to difficulties in controlling the quantum dot size and distribution during epitaxy. [reprint (PDF)]

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