Center for Quantum Devices - Most Downloaded Journal Articles

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15.	Inductively coupled plasma etching and processing techniques for type-II InAs/GaSb superlattices infrared detectors toward high fill factor focal plane arrays E.K. Huang, B.M. Nguyen, D. Hoffman, P.Y. Delaunay and M. Razeghi SPIE Proceedings, San Jose, CA Volume 7222-0Z-- January 26, 2009 ...[Visit Journal] A challenge for Type-II InAs/GaSb superlattice (T2SL) photodetectors is to achieve high fill factor, high aspect ratio etching for third generation focal plane arrays (FPAs). Initially, we compare the morphological and electrical results of single element T2SL photodiodes after BCl₃/Ar inductively coupled plasma (ICP) and electron cyclotron resonance (ECR) dry etching. Using a Si₃N₄ hard mask, ICP-etched structures exemplify greater sidewall verticality and smoothness, which are essential toward the realization of high fill factor FPAs. ICP-etched single element devices with SiO₂ passivation that are 9.3 µm in cutoff wavelength achieved vertical sidewalls of 7.7 µm in depth with a resistance area product at zero bias of greater than 1,000 Ω·cm² and maximum differential resistance in excess of 10,000 Ω·cm² at 77 K. By only modifying the etching technique in the fabrication steps, the ICP-etched photodiodes showed an order of magnitude decrease in their dark current densities in comparison to the ECR-etched devices. Finally, high aspect ratio etching is demonstrated on mutli-element arrays with 3 µm-wide trenches that are 11 µm deep. [reprint (PDF)]
15.	320x256 infrared focal plane array based on type-II InAs/GaSb superlattice with a 12 μm cutoff wavelength P.Y. Delaunay, B.M. Nguyen, D. Hoffman, and M. Razeghi SPIE Porceedings, Vol. 6542, Orlando, FL 2007, p. 654204-- April 9, 2007 ...[Visit Journal] In the past few years, significant progress has been made in the structure design, growth and processing of Type-II InAs/GaSb superlattice photodetectors. Type-II superlattice demonstrated its ability to perform imaging in the middle and long infra-red range, becoming a potential competitor for technologies such as QWIP and HgCdTe. Using an empirical tight-binding model, we developed a superlattice design that matches the lattice parameter of GaSb substrates and presents a cutoff wavelength of 12 μm. Electrical and optical measurements performed on single element detectors at 77 K showed an R₀A averaging 13 Ω·cm² and a quantum efficiency as high as 54%. We demonstrated high quality material growth with x-ray FWHM below 30 arcsec and an AFM rms roughness of 1.5 Å over an area of 20x20 μm². A 320x256 array of 25x25μm² pixels, hybridized to an Indigo Read Out Integrated Circuit, performed thermal imaging up to 185 K with an operability close to 97%. The noise equivalent temperature difference at 81 K presented a peak at 270 mK, corresponding to a mean value of 340 mK. [reprint (PDF)]
15.	Infrared detection from GaInAs/InP nanopillar arrays A. Gin, B. Movaghar, M. Razeghi and G.J. Brown Nanotechnology 16-- July 1, 2005 ...[Visit Journal] We report on the photoresponse from large arrays of 40 nm radius nanopillars with sensitivity in the long-wavelength infrared regime. Using photoluminescence techniques, a peak wavelength blue shift of approximately 5 meV was observed at 30 K from GaInAs/InP nanopillar structures, indicating carrier confinement effects. Responsivity measurements at 30 K indicated peak wavelength response at about 8 µm with responsivity of 420 mA/W at −2 V bias. We have also measured the noise and estimated the peak detectivity to be 3×10⁸ cm·Hz^½·W⁻¹ at 1 V reverse bias and 30 K. A maximum internal quantum efficiency of 4.5% was derived from experiment. Both the photo and the dark transport have been successfully modeled as processes that involve direct and indirect field-assisted tunneling as well as thermionic emission. The best agreement with experiment was obtained when allowances were made for the non-uniformity of barrier widths and electric field heating of carriers above the lattice temperature. [reprint (PDF)]
15.	Room‐temperature excitons in Ga0.47In0.53As‐InP superlattices grown by low‐pressure metalorganic chemical vapor deposition M. Razeghi; J. Nagle; P. Maurel; F. Omnes; J. P. Pocholle Appl. Phys. Lett. 49, 1110–1111 (1986)-- October 27, 1986 ...[Visit Journal] Very high quality Gao.47 InO. 53 As-InP heterojunctions, quantum wells, and superlattices have been grown by low-pressure metalorganic chemical vapor deposition. Excitation spectroscopy shows evidence of strong and wen-resolved exciton peaks in the luminescence and excitation spectra of GalnAs-lnP quantum wells. Optical absorption spectra show room-temperature excitons in GalnAs· InP superlattices. [reprint (PDF)]
15.	High differential resistance type-II InAs/GaSb superlattice photodiodes for the long-wavelength infrared A. Hood, D. Hoffman, B.M. Nguyen, P.Y. Delaunay, E. Michel and M. Razeghi Applied Physics Letters, 89 (9)-- August 28, 2006 ...[Visit Journal] Type-II InAs/GaSb superlattice photodiodes with a 50% cutoff wavelength ranging from 11 to 13 μm are presented. Optimization of diffusion limited photodiodes provided superlattice structures for improved injection efficiency in direct injection hybrid focal plane array applications. [reprint (PDF)]
15.	On the interface properties of ZnO/Si electroluminescent diodes J.L. Pau, J. Piqueras, D.J. Rogers, F. Hosseini Teherani, K. Minder, R. McClintock, and M. Razeghi Journal of Applied Physics, Vol. 107, No. 3, p. 033719-1-- February 1, 2010 ...[Visit Journal] ZnO layers grown on n⁻–Si(100), n⁺–Si(100), and n^––Si(111) substrates by pulsed-laser deposition were found to give electroluminescence. Light emission was observed in the form of discrete spots for currents over 1 mA with a white appearance to the naked eye. The intensity of these spots showed an erratic behavior over time, appearing and disappearing at random, while showing an associated random telegraph noise in the current signal. Regardless the substrate used, the electroluminescence spectra had a main broadband emission centered at about 600 nm and a relatively small peak at around 380 nm which corresponds to the energy of ZnO near band edge emission. Furthermore, the devices exhibited rectifying characteristics, whose current blocking direction depended on the substrate orientation. Optimization of ZnO conductivity and performing sample growth in N₂ ambient were found to be critical to enhance the emission intensity. Rutherford backscattering characterization revealed the existence of an intermixed region at the interface between ZnO and Si. To study the electronic properties at the interface, frequency dependent capacitance measurements were carried out. The junction capacitance became frequency dependent at the bias voltages at which light emission occurs due to the relatively slow trapping and generation processes at deep centers. These centers are believed to play an important role in the mechanism of light emission. [reprint (PDF)]
15.	Electrically pumped photonic crystal distributed feedback quantum cascade lasers Y. Bai, P. Sung, S.R. Darvish, W. Zhang, A. Evans, S. Slivken, and M. Razeghi SPIE Conference, January 20-25, 2008, San Jose, CA Proceedings – Quantum Sensing and Nanophotonic Devices V, Vol. 6900, p. 69000A-1-8.-- February 1, 2008 ...[Visit Journal] We demonstrate electrically pumped, room temperature, single mode operation of photonic crystal distributed feedback (PCDFB) quantum cascade lasers emitting at ~ 4.75 µm. Ridge waveguides of 50 µm and 100 µm width were fabricated with both PCDFB and Fabry-Perot feedback mechanisms. The Fabry-Perot device has a broad emitting spectrum and a broad far-field character. The PCDFB devices have primarily a single spectral mode and a diffraction limited far field characteristic with a full angular width at half-maximum of 4.8 degrees and 2.4 degrees for the 50 µm and 100 µm ridge widths, respectively. [reprint (PDF)]
15.	Electron capture processes in optically excited In0.53Ga 0.47As/InP quantum wells U. Cebulla, G. Bacher, A. Forchel, D. Schmitz, H. Jürgensen, M. Razeghi Appl. Phys. Lett. 55, 933–935 (1989)-- September 4, 1989* ...[Visit Journal] We have performed picosecond time-resolved measurements on Ir:.O. 53 GaO. 47 As/lnP quantum wells with varying barrier thicknesses using 10 ps Nd:Y AG excitation. For this excitation, holes and electrons are created in the Ino . 53 GaOA7 As layers. Due to momentum conservation the Nd:YAG excitation accelerates the electrons above the InP barrier where they can diffuse but cannot recombine. By examining the rise time of the quantum well emission, we can show that for samples with thick barriers, the harrier geometry largely controls the dynamic properties of the carriers after Nd:YAG excitation. [reprint (PDF)]
15.	Single-mode, high-power, midinfrared, quantum cascade laser phased arrays Wenjia Zhou , Donghai Wu , Quan-Yong Lu, Steven Slivken & Manijeh Razeghi Scientific Reports 8:14866-- October 5, 2018 ...[Visit Journal] We demonstrate single-mode, 16-channel, optical phased arrays based on quantum cascade laser technology, with emission wavelengths around 4.8 μm. The integrated device consists of a distributed feedback seed section, a highly-efficient tree array multi-mode interferometer power splitter, and a 16-channel amplifier array with a 4° angled facet termination. With a single layer Y₂O₃ coating, the angled facet reflectivity is estimated to be less than 0.1% for suppressing amplifier self-lasing. A peak output power of 30 W is achieved with an emission spectrum narrower than 11 nm and a side mode suppression ratio over 25 dB. Far field distribution measurement result indicates a uniform phase distribution across the array output. Using the same phased array architecture, we also demonstrate single-mode 3.8 μm QCL amplifier arrays with up to 20 W output power. [reprint (PDF)]
15.	Band-gap narrowing and potential fluctuation in Si-doped GaN I.H. Lee, J.J. Lee, P. Kung, F.J. Sanchez, and M. Razeghi Applied Physics Letters 74 (1)-- January 4, 1999 ...[Visit Journal] We investigate the optical properties of two sets of Si-doped GaN epitaxial layers with different degree of compensation. The electron concentration dependence of the band-gap energy measured by photoluminescence is interpreted as band-gap narrowing effect and evaluated by a simple relation. The photoluminescence peak positions of heavily compensated samples are shifted downward with respect to those of moderately compensated samples, and the down shift becomes larger at higher electron density. Based on analysis of photoluminescence spectra, these prominent behaviors are accounted for by band-edge potential fluctuation associated with inhomogeneous residual impurities. [reprint (PDF)]
15.	Radiative recombination of confined electrons at the MgZnO/ ZnO heterojunction interface Sumin Choi, David J. Rogers, Eric V. Sandana, Philippe Bove, Ferechteh H. Teherani, Christian Nenstiel, Axel Hoffmann, Ryan McClintock, Manijeh Razeghi, David Look, Angus Gentle, Matthew R. Phillips & Cuong Ton-That Nature Scientific Reports 7, pp. 7457-- August 7, 2017 ...[Visit Journal] We investigate the optical signature of the interface in a single MgZnO/ZnO heterojunction, which exhibits two orders of magnitude lower resistivity and 10 times higher electron mobility compared with the MgZnO/Al₂O₃ film grown under the same conditions. These impressive transport properties are attributed to increased mobility of electrons at the MgZnO/ZnO heterojunction interface. Depthresolved cathodoluminescence and photoluminescence studies reveal a 3.2 eV H-band optical emission from the heterointerface, which exhibits excitonic properties and a localization energy of 19.6 meV. The emission is attributed to band-bending due to the polarization discontinuity at the interface, which leads to formation of a triangular quantum well and localized excitons by electrostatic coupling. [reprint (PDF)]
15.	Electrically pumped photonic crystal distributed feedback quantum cascade lasers Y. Bai, S.R. Darvish, S. Slivken, P. Sung, J. Nguyen, A. Evans, W. Zhang, and M. Razeghi Applied Physics Letters, Vol. 91, No. 14, p. 141123-1-- October 1, 2007 ...[Visit Journal] We demonstrate electrically pumped, room temperature, single mode operation of photonic crystal distributed feedback (PCDFB) quantum cascade lasers emitting at ~4.75 µm. Ridge waveguides of 100 µm width were fabricated with both PCDFB and Fabry-Pérot feedback mechanisms. The Fabry-Pérot device has a broad emitting spectrum and a double lobed far-field character. The PCDFB device, as expected, has primarily a single spectral mode and a diffraction limited far field characteristic with a full angular width at half maximum of 2.4°. This accomplishment represents the first step in power scaling of single mode, midinfrared laser diodes operating at room temperature. [reprint (PDF)]
15.	High Power, Continuous-Wave, Quantum Cascade Lasers for MWIR and LWIR Applications S. Slivken, A. Evans, J.S. Yu, S.R. Darvish and M. Razeghi SPIE Conference, San Jose, CA, Vol. 6127, pp. 612703-- January 23, 2006 ...[Visit Journal] Over the past several years, our group has endeavored to develop high power quantum cascade lasers for a variety of remote and high sensitivity infrared applications. The systematic optimization of laser performance has allowed for demonstration of high power, continuous-wave quantum cascade lasers operating above room temperature. Since 2002, the power levels for individual devices have jumped from 20 mW to 600 mW. Expanding on this development, we have able to demonstrate continuous wave operation at many wavelengths throughout the mid- and far-infrared spectral range, and have now achieved >100 mW output in the 4.0 to 9.5 µm range. [reprint (PDF)]
15.	Temperature insensitivity of the Al-free InGaAsP/GaAs lasers for λ = 808 and 908 nm M. Razeghi, H. Yi, J. Diaz, S. Kim, and M. Erdtmann SPIE Conference, San Jose, CA; Proceedings 3001-- February 12, 1997 ...[Visit Journal] n this work, we present our recent achievements for the reliability of the Al-free lasers at high temperatures and high powers. Laser operations up to 30,000 hours were achieved without any degradation in the lasers characteristics from 7 randomly selected InGaAsP/GaAs diodes for λ = 808 nm. The test were performed for lasers without mirror-coating for optical power of 0.5 to 1 W CW at 50 approximately 60 °C. To the best of our knowledge, this is the first direct demonstration of the extremely high reliability of Al-free diodes operations at high powers and temperatures for periods of time much longer than practical need (approximately 3 years). The characteristics during the tests are discussed in detail. [reprint (PDF)]
15.	InGaAs/InGaP Quantum-Dot Photodetector with a High Detectivity H. Lim, S. Tsao, M. Taguchi, W. Zhang, A. Quivy and M. Razeghi SPIE Conference, San Jose, CA, Vol. 6127, pp. 61270N-- January 23, 2006 ...[Visit Journal] Quantum-dot infrared photodetectors (QDIPs) have recently been considered as strong candidates for numerous applications such as night vision, space communication, gas analysis and medical diagnosis involving middle and long wavelength infrared (MWIR and LWIR respectively) operation. This is due to their unique properties arising from their 3-dimensional confinement potential that provides a discrete density of states. They are expected to outperform quantum-well infrared photodetectors (QWIPs) as a consequence of their natural sensitivity to normal incident radiation, their higher responsivity and their higher-temperature operation. So far, most of the QDIPs reported in the literature were based on the InAs/GaAs system and were grown by molecular beam epitaxy (MBE). Here, we report on the growth of a high detectivity InGaAs/InGaP QDIP grown on a GaAs substrate using low-pressure metalorganic chemical vapor deposition (MOCVD). [reprint (PDF)]
15.	A hybrid green light-emitting diode comprised of n-ZnO/(InGaN/GaN) multi-quantum-wells/p-GaN C. Bayram, F. Hosseini Teherani, D.J. Rogers and M. Razeghi Applied Physics Letters, Vol. 93, No. 8, p. 081111-1-- August 25, 2008 ...[Visit Journal] Hybrid green light-emitting diodes (LEDs) comprised of n-ZnO/(InGaN/GaN) multi-quantum-wells/p-GaN were grown on semi-insulating AlN/sapphire using pulsed laser deposition for the n-ZnO and metal organic chemical vapor deposition for the other layers. X-ray diffraction revealed that high crystallographic quality was preserved after the n-ZnO growth. LEDs showed a turn-on voltage of 2.5 V and a room temperature electroluminescence (EL) centered at 510 nm. A blueshift and narrowing of the EL peak with increasing current was attributed to bandgap renormalization. The results indicate that hybrid LED structures could hold the prospect for the development of green LEDs with superior performance. [reprint (PDF)]
15.	Reliability of Aluminum-Free 808 nm High-Power Laser Diodes with Uncoated Mirrors I. Eliashevich, J. Diaz, H. Yi, L. Wang, and M. Razeghi Applied Physics Letters 66 (23)-- June 5, 1995 ...[Visit Journal] The reliability of uncoated InGaAsP/GaAs high‐power diode lasers emitting at 808 nm wavelength has been studied. 47 W of quasicontinuous wave output power (pulse width 200 μs, frequency 20 Hz) have been obtained from a 1 cm wide laser bar. A single‐stripe diode without mirror coating has been life tested at 40 °C for emitting power of 800 mW continuous wave (cw) and showed no noticeable degradation and no change of the lasing wavelength after 6000 h of operation. [reprint (PDF)]
15.	Optical losses of Al-free lasers for λ = 0.808 and 0.98 μm H. Yi, J. Diaz, B. Lane, and M. Razeghi Applied Physics Letters 69 (20)-- November 11, 1996 ...[Visit Journal] In this work, we study the origin of the optical losses in Al‐free InGaAsP/GaAs (λ=0.808 μm) and InGaAs/GaAs/InGaP (λ=0.980 μm) lasers. Theoretical modeling and the experimental results indicate that the scattering of the laser beam by refractive index fluctuation in the alloys is the dominant loss in our lasers, and the loss due to the free‐carrier absorption and scattering by interface roughness are negligible. [reprint (PDF)]
15.	Band edge tunability of M-structure for heterojunction design in Sb based Type-II superlattice photodiodes B.M. Nguyen, D. Hoffman, P.Y. Delaunay, E.K. Huang, M. Razeghi, and J. Pellegrino Applied Physics Letters, Vol. 93, No. 16, p. 163502-1-- October 20, 2008 ...[Visit Journal] We present theoretically and experimentally the effect of the band discontinuity in Type-II misaligned InAs/GaSb superlattice heterodiodes. Calculations using the empirical tight binding method have shown the great flexibility in tuning the energy levels of the band edge in M-structure superlattice as compared to the standard InAs/GaSb superlattice. Through the experimental realization of several p-pi-M-n photodiodes, the band discontinuity alignment between the standard binary-binary superlattice and the M-structured superlattice was investigated via optical characterization. The agreement between the theoretical predictions and the experimental measurement confirms the capability of controlling the M-structure band edges and suggests a way to exploit this advantage for the realization of heterostructures containing an M-structured superlattice without bias dependent operation. [reprint (PDF)]
15.	Comparison of PLD-Grown p-NiO/n-Ga2O3 Heterojunctions on Bulk Single Crystal β-Ga2O3 and r-plane Sapphire Substrates D. J. Rogers , V. E. Sandana, F. Hosseini Teherani and M. Razeghi Proc. of SPIE Vol. 12895, Quantum Sensing and Nano Electronics and Photonics XX, 128870J (28 January - 1 February 2024 San Francisco)doi: 10.1117/12.3012511 ...[Visit Journal] p-NiO/n-Ga2O3 heterostructures were formed on single crystal (-201) β (monoclinic) Ga2O3 and r-sapphire substrates by Pulsed Laser Deposition. Ring mesa layer stacks were created using a shadow mask during growth. X-Ray diffraction studies were consistent with the formation of (111) oriented fcc NiO on the bulk Ga2O3 and randomly oriented fcc NiO on (102) oriented β-Ga2O3 /r-sapphire. RT optical transmission studies revealed bandgap energy values of ~3.65 eV and ~5.28 eV for the NiO and Ga2O3 on r-sapphire. p-n junction devices were formed by depositing gold contacts on the layer stacks using shadow masks in a thermal evaporator. Both heterojunctions showed rectifying I/V characteristics. On bulk Ga2O, the junction showed a current density over 16mA/cm2 at +20V forward bias and a reverse bias leakage current over 3 orders of magnitude lower at -20V (1 pA). On Ga2O3/r-sapphire the forward bias current density at +15V was about an order of magnitude lower than for the p-NiO/bulk n-Ga2O3 heterojunction while the reverse bias leakage current at -15V (~ 20 pA) was an order of magnitude higher. Hence the NiO/bulk Ga2O3 junction was more rectifying. Upon illumination with a Xenon lamp a distinct increase in current was observed for the IV curves in both devices (four orders of magnitude for -15V reverse bias in the case of the p-NiO/bulk n-Ga2O3 heterojunction). The p-NiO/n-Ga2O3/rsapphire junction gave a spectral responsivity with a FWHM value of 80nm and two distinct response peaks (with maxima at 230 and 270nm) which were attributed to carriers being photogenerated in the Ga2O3 underlayer. For both devices time response studies showed a 10%/90% rise and fall of the photo generated current upon shutter open and closing which was relatively abrupt (millisecond range), and there was no evidence of significant persistent photoconductivity. [reprint (PDF)]
15.	Growth of Al_xGa_1-xN:Ge on sapphire and silicon substrates X. Zhang, P. Kung, A. Saxler, D. Walker, T.C. Wang, and M. Razeghi Applied Physics Letters 67 (12)-- September 18, 1995 ...[Visit Journal] Al_xGa_1–xN were grown on (00.1) sapphire and (111) silicon substrates in the whole composition range (0 <= x <= 1). The high optical quality of the epilayers was assessed by room-temperature optical absorption and photoluminescence measurements. Layers with higher Al composition are more resistive. Resistive Al_xGa_1–xN epilayers were successfully doped with Ge and free-electron concentration as high as 3 × 10¹⁹ cm^–3 was achieved. [reprint (PDF)]
15.	Overview of Quantum Cascade Laser Research at the Center for Quantum Devices S. Slivken, A. Evans, J. Nguyen, Y. Bai, P. Sung, S.R. Darvish, W. Zhang and M. Razeghi SPIE Conference, January 20-25, 2008, San Jose, CA Proceedings – Quantum Sensing and Nanophotonic Devices V, Vol. 6900, p. 69000B-1-8.-- February 1, 2008 ...[Visit Journal] Over the past several years, our group has endeavored to develop high power quantum cascade lasers for a variety of remote and high sensitivity infrared applications. The systematic optimization of laser performance has allowed for demonstration of high power, continuous-wave quantum cascade lasers operating above room temperature. In the past year alone, the efficiency and power of our short wavelength lasers (~4.8 µm) has doubled. In continuous wave at room temperature, we have now separately demonstrated ~10% wallplug efficiency and ~700 mW of output power. Up to now, we have been able to show that room temperature continuous wave operation with > 100 mW output power in the 3.8 < λ < 11.5 µm wavelength range is possible. [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.	Bias-selectable three-color short-, extended-short-, and mid-wavelength infrared photodetectors based on type-II InAs/GaSb/AlSb superlattices Abbas Haddadi, and Manijeh Razeghi Optics Letters Vol. 42, Iss. 21, pp. 4275-4278-- October 16, 2017 ...[Visit Journal] A bias-selectable, high operating temperature, three-color short-, extended-short-, and mid-wavelength infrared photodetector based on InAs/GaSb/AlSb type-II superlattices on GaSb substrate has been demonstrated. The short-, extended-short-, and mid-wavelength channels’ 50% cutoff wavelengths were 2.3, 2.9, and 4.4μm, respectively, at 150K. The mid-wavelength channel exhibited a saturated quantum efficiency of 34% at 4μm under +200 mV bias voltage in a front-side illumination configuration and without any antireflection coating. At 200mV, the device exhibited a dark current density of 8.7×10⁻⁵ A/cm² providing a specific detectivity of ∼2×10¹¹ cm·Hz^1/2/W at 150K. The short-wavelength channel achieved a saturated quantum efficiency of 20% at 1.8μm. At −10 mV, the device’s dark current density was 5.5×10⁻⁸ A/cm². At zero bias, its specific detectivity was 1×10¹¹ cm·Hz^1/2/W at 150K. The extended short-wavelength channel achieved a saturated quantum efficiency of 22% at 2.75 μm. Under −2 V bias voltage, the device exhibited a dark current density of 1.8×10⁻⁶ A/cm² providing a specific detectivity of 6.3×10¹¹ cm·Hz^1/2/W at 150K. [reprint (PDF)]
15.	High-Performance Focal Plane Arrays Based on InAs-GaSb Superlattices with a 10-micron Cutoff Wavelegth P.Y. Delaunay, B.M. Nguyen, D. Hoffman and M. Razeghi IEEE Journal of Quantum Electronics, Vol. 44, No. 5, p. 462-467-- May 1, 2008 ...[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)]

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