Center for Quantum Devices - Most Downloaded Journal Articles

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18.	MOCVD Growth of ZnO Nanostructures Using Au Droplets as Catalysts V.E. Sandana, D.J. Rogers, F.H. Teherani, R. McClintock, M. Razeghi, H.J. Drouhin, M.C. Clochard, V. Sallett, G. Garry and F. Fayoud SPIE Conference, January 20-25, 2008, San Jose, CA Proceedings – Zinc Oxide Materials and Devices III, Vol. 6895, p. 68950Z-1-6.-- February 1, 2008 ...[Visit Journal] ZnO nanostructures were synthesised by Metal Organic Chemical Vapor Deposition growth on Si (100) and c-Al₂O₃ substrates coated with a 5nm thick layer of Au. The Au coated substrates were annealed in air prior to deposition of ZnO so as to promote formation of Au nanodroplets. The development of the nanodroplets was studied as a function of annealing duration and temperature. Under optimised conditions, a relatively homogeneous distribution of regular Au nanodroplets was obtained. Using the Au nanodroplets as a catalyst, MOCVD growth of ZnO nanostructures was studied. Scanning electron microscopy revealed nanostructures with various forms including commonly observed structures such as nanorods, nanoneedles and nanotubes. Some novel nanostructures were also observed, however, which resembled twist pastries and bevelled-multifaceted table legs. [reprint (PDF)]
18.	AlGaN ultraviolet detectors M. Razeghi and A. Rogalski, SPIE Conference, San Jose, CA, -- February 12, 1997 ...[Visit Journal] Hitherto, the semiconductor ultraviolet (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 efforts are currently directed to anew 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 described in detail. [reprint (PDF)]
18.	A detailed analysis of carrier transport in InAs0.3Sb0.7 layers grown on GaAs substrates by metalorganic chemical vapor deposition C. Besikci, Y.H. Choi, G. Labeyrie, E. Bigan and M. Razeghi with J.B. Cohen, J. Carsello, and V.P. Dravid Journal of Applied Physics 76 (10)-- November 15, 1994 ...[Visit Journal] InAs_0.3Sb_0.7 layers with mirrorlike morphology have been grown on GaAs substrates by low‐pressure metalorganic chemical vapor deposition. A room‐temperature electron Hall mobility of 2×10⁴ cm²/V· s has been obtained for a 2 μm thick layer. Low‐temperature resistivity of the layers depended on TMIn flow rate and layer thickness. Hall mobility decreased monotonically with decreasing temperature below 300 K. A 77 K conductivity profile has shown an anomalous increase in the sample conductivity with decreasing thickness except in the near vicinity of the heterointerface. In order to interpret the experimental data, the effects of different scattering mechanisms on carrier mobility have been calculated, and the influences of the lattice mismatch and surface conduction on the Hall measurements have been investigated by applying a three‐layer Hall‐effect model. Experimental and theoretical results suggest that the combined effects of the dislocations generated by the large lattice mismatch and strong surface inversion may lead to deceptive Hall measurements by reflecting typical n‐type behavior for a p‐type sample, and the measured carrier concentration may considerably be affected by the surface conduction up to near room temperature. A quantitative analysis of dislocation scattering has shown significant degradation in electron mobility for dislocation densities above 10⁷ cm⁻². The effects of dislocation scattering on hole mobility have been found to be less severe. It has also been observed that there is a critical epilayer thickness (∼1 μm) below which the surface electron mobility is limited by dislocation scattering. [reprint (PDF)]
18.	Temperature dependence of threshold current density J_th and differential efficiency of High Power InGaAsP/GaAs ( λ = 0.8 μm) lasers H. Yi, J. Diaz, I. Eliashevich, M. Stanton, M. Erdtmann, X. He, L. Wang, and M. Razeghi Applied Physics Letters 66 (3)-- January 16, 1995 ...[Visit Journal] An experimental and theoretical study on temperature dependence of the threshold current density J_th and differential efficiency ηd for the InGaAsP/GaAs laser diodes emitting at λ=0.8 μm was performed. Threshold current density J_th increases and differential efficiency η_d decreases as temperature is increased mainly because of thermal broadening of the gain spectrum. However, the measured temperature dependence of J_th and η_d could not be explained when only this effect was considered. In this letter, the temperature dependence of momentum relaxation rate ℏ/τ of carriers was investigated by performing the photoluminescence study. At high temperature, increase of the momentum relaxation rate ℏ/τ leads to reduction of the gain and mobility and increase of the optical loss, causing higher J_th and lower η_d as experimentally observed. The resulting theoretical model provides a good explanation for the mechanism of the increase of J_th and decrease of η_d. [reprint (PDF)]
18.	EPR investigation of Gd3+ and Eu2+ in the α- and β-phases of lead phosphate M. RAZEGHI, J. P. BUISSON, and B. HOULIE M. RAZEGHI et al.: EPR Investigation of Gd3+ and Eu2+ in Lead Phosphate phys. stat. sol. (b) 96, 283 (1979-- September 1, 1979 ...[Visit Journal] The X-band EPR spectra of Gd3+and Eu2+diluted in Pb3(P04)2crystals are studied. Lead phos-phate exhibits a ferroelastic phase transition a t 180 “C and the EPR spectra obtained in eachphase differ from each other. The spectra are very complex because the zero field splitting hasthe same order of magnitude as the Zeeman term. The spin Hamiltonian parameters and theenergy levels are computed. “Forbidden” or “missing” transitions and line intensities can beexplained. [reprint (PDF)]
18.	High operating temperature 320 x 256 middle-wavelength infrared focal plane array imaging based on an InAs/InGaAs/InAlAs/InP quantum dot infrared photodetector S. Tsao, H. Lim, W. Zhang, and M. Razeghi Applied Physics Letters, Vol. 90, No. 20, p. 201109-- May 14, 2007 ...[Visit Journal] This letter reports a 320×256 middle-wavelength infrared focal plane array operating at temperatures up to 200 K based on an InAs quantum dot/InGaAs quantum well/InAlAs barrier detector grown on InP substrate by low pressure metal organic chemical vapor deposition. The device's low dark current density and the persistence of the photocurrent up to room temperature enabled the high temperature imaging. The focal plane array had a peak detection wavelength of 4 µm, a responsivity of 34 mA/W, a conversion efficiency of 1.1%, and a noise equivalent temperature difference of 344 mK at an operating temperature of 120 K. [reprint (PDF)]
18.	High-power λ ~ 9.5 µm quantum-cascade lasers operating above room temperature in continuous-wave mode J.S. Yu, S. Slivken, A. Evans, S.R. Darvish, J. Nguyen, and M. Razeghi Applied Physics Letters, 88 (9)-- February 27, 2006 ...[Visit Journal] We report high-power continuous-wave (cw) operation of λ~9.5 μm quantum-cascade lasers to a temperature of 318 K. A high-reflectivity-coated 19-μm-wide and 3-mm-long device exhibits cw output powers as high as 150 mW at 288 K and still 22 mW at 318 K. In cw operation at 298 K, a threshold current density of 1.57 kA/cm², a slope efficiency of 391 mW/A, and a maximum wall-plug efficiency of 0.71% are obtained. [reprint (PDF)]
18.	Advanced Monolithic Quantum Well Infrared Photodetector Focal Plane Array Integrated with Silicon Readout Integrated Circuit J. Jiang, S. Tsao, K. Mi, M. Razeghi, G.J. Brown, C. Jelen and M.Z. Tidrow Infrared Physics and Technology, 46 (3)-- January 1, 2005 ...[Visit Journal] Today, most infrared focal plane arrays (FPAs) utilize a hybrid scheme. To achieve higher device reliability and lower cost, monolithic FPAs with Si based readout integrated circuits (ROICs) are the trend of the future development. In this paper, two approaches for monolithic FPAs are proposed: double sided integration and selective epitaxy integration. For comparison, the fabrication process for hybrid quantum well infrared photodetectors (QWIP) FPAs are also described. Many problems, such as the growth of QWIPs on Si substrate and processing incompatibility between Si and III–V semiconductors, need to be solved before monolithic FPAs can be realized. Experimental work on GaInAs/InP QWIP-on-Si is given in this paper. A record high detectivity of 2.3×10⁹ jones was obtained for one QWIP-on-Si detector at 77 K. [reprint (PDF)]
18.	A lifetime of contributions to the world of semiconductors using the Czochralski invention Manijeh Razeghi Journal of Vacuum Volume 146, Pages 308-328-- December 1, 2017 ...[Visit Journal] Over the course of my career, I have made numerous contributions related to semiconductor crystal growth and high performance optoelectronics over a vast region of the electromagnetic spectrum (ultraviolet to terahertz). In 2016 this cumulated in my receiving the Jan Czochralski Gold Medal award from the European Materials Research Society. This article is designed to provide a historical perspective and general overview of these scientific achievements, on the occasion of being honored by this award. These achievements would not have been possible without high quality crystalline substrates, and this article is written in honor of Jan Czochralski on the 100th anniversary of his important discovery. [reprint (PDF)]
18.	High power asymmetrical InAsSb/InAsSbP/AlAsSb double heterostructure lasers emitting at 3.4 μm D. Wu, B. Lane, H. Mohseni, J. Diaz and M. Razeghi Applied Physics Letters 74 (9)-- March 1, 1999 ...[Visit Journal] Midinfrared lasers with an asymmetrical InPAsSb/InAsSb/AlAsSb double heterostructure are reported. Using the asymmetrical double heterostructure, p- and n-cladding layers are separately optimized; high energy-gap AlAsSb (Eg ≈ 1.5 eV) for the p-type cladding layer to reduce the leakage current, and thus to increase To, and low energy-gap InPAsSb (Eg ≈ 0.5 eV) for the n-cladding layer to have low turn-on voltage. 100-μm-width broad-area lasers with 1000 μm cavity length exhibited peak output powers of 1.88 W in pulse and 350 mW in continuous wave modes per two facets at T=80 K with To of 54 K and turn-on voltage of 0.36 V. Maximum peak output powers up to 6.7 W were obtained from a laser bar of total aperture of 400 μm width and cavity length of 1000 μm, with a differential efficiency of 34% and far-field beam divergence narrower than 40° at 80 K. [reprint (PDF)]
18.	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)]
18.	Sampled grating, distributed feedback quantum cascade lasers with broad tunability and continuous operation at room temperature S. Slivken, N. Bandyopadhyay, S. Tsao, S. Nida, Y. Bai, Q.Y. Lu and M. Razeghi Applied Physics Letters, Vol. 100, No. 26, p. 261112-1-- June 25, 2012 ...[Visit Journal] A dual-section, single-mode quantum cascade laser is demonstrated in continuous wave at room temperature with up to 114 nm (50 cm⁻¹) of tuning near a wavelength of 4.8 μm. Power above 100 mW is demonstrated, with a mean side mode suppression ratio of 24 dB. By changing the grating period, 270 nm (120 cm⁻¹) of gap-free electrical tuning for a single gain medium has been realized. [reprint (PDF)]
18.	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)]
18.	Tunability of intersubband absorption from 4.5 to 5.3 µm in a GaN/Al_0.2Ga_0.8N superlattices grown by metalorganic chemical vapor deposition N. Péré-Laperne, C. Bayram, L. Nguyen-Thê, R. McClintock, and M. Razeghi Applied Physics Letters, Vol. 95, No. 13, p. 131109-- September 28, 2009 ...[Visit Journal] Intersubband (ISB) absorption at wavelengths as long as 5.3 µm is realized in GaN/Al_0.2Ga_0.8N superlattices grown by metalorganic chemical vapor deposition. By employing low aluminum content Al_0.2Ga_0.8N barriers and varying the well width from 2.6 to 5.1 nm, ISB absorption has been tuned from 4.5 to 5.3 µm. Theoretical ISB absorption and interband emission models are developed and compared to the experimental results. The effects of band offsets and the piezoelectric fields on these superlattices are investigated. [reprint (PDF)]
18.	Uncooled operation of Type-II InAs/GaSb superlattice photodiodes in the mid- wavelength infrared range Y. Wei, A. Hood, H. Yau, A. Gin, M. Razeghi, M.Z. Tidrow, V. Natha Applied Physics Letters, 86 (23)-- June 6, 2005 ...[Visit Journal] We report high performance uncooled midwavelength infrared photodiodes based on interface-engineered InAs/GaSb superlattice. Two distinct superlattices were designed with a cutoff wavelength around 5 µm for room temperature and 77 K. The device quantum efficiency reached more than 25% with responsivity around 1 A/W. Detectivity was measured around 10⁹ cm·Hz^½/W at room temperature and 1.5×10¹³ cm·Hz^½/W at 77 K under zero bias. The devices were without antireflective coating. The device quantum efficiency stays at nearly the same level within this temperature range. Additionally, Wannier–Stark oscillations in the Zener tunneling current were observed up to room temperature. [reprint (PDF)]
18.	High-performance short-wavelength infrared photodetectors based on type-II InAs/InAs1-xSbx/AlAs1-xSbx superlattices A. Haddadi, X.V. Suo, S. Adhikary, P. Dianat, R. Chevallier, A.M. Hoang, and M. Razeghi Applied Physics Letters 107 , 141104-- October 5, 2015 ...[Visit Journal] A high-performance short-wavelength infrared n-i-p photodiode based on InAs/InAs1-xSbx/AlAs1-xSbx type-II superlattices on GaSb substrate has been demonstrated. The device is designed to have a 50% cut-off wavelength of ~1.8μm at 300K. The photodetector exhibited a room-temperature (300 K) peak responsivity of 0.47 A/W at 1.6μm, corresponding to a quantum efficiency of 37% at zero bias under front-side illumination, without any anti-reflection coating. With an R×A of 285 Ω·cm² and a dark current density of 9.6×10^-5 A/cm² under −50mV applied bias at 300 K, the photodiode exhibited a specific detectivity of 6.45×10¹⁰ cm·Hz^½/W. At 200 K, the photodiode exhibited a dark current density of 1.3×10^-8 A/cm² and a quantum efficiency of 36%, resulting in a detectivity of 5.66×10¹² cm·Hz^½/W. [reprint (PDF)]
18.	Schottky MSM Photodetectors on GaN Films Grown on Sapphire by Lateral Epitaxial Overgrowth P. Kung, D. Walker, P. Sandvik, M. Hamilton, J. Diaz, I.H. Lee and M. Razeghi SPIE Conference, San Jose, CA, -- January 27, 1999 ...[Visit Journal] We report the growth and characterization of Schottky based metal-semiconductor-metal ultraviolet photodetectors fabricated on lateral epitaxially overgrown GaN films. The lateral epitaxial overgrowth of GaN was carried out on basal plane sapphire substrates by low pressure metalorganic chemical vapor deposition and exhibited lateral growth rates more than 5 times as high as vertical growth rates. The spectral responsivity, the dependence on bias voltage, on incident optical power, and the time response of these photodetectors have been characterized. Two detector orientations were investigated: one with the interdigitated finger pattern parallel and the other perpendicular to the underlying SiO_x mask stripes. [reprint (PDF)]
18.	AlGaN/AlN MOVPE heteroepitaxy: pulsed co-doping SiH4 and TMIn Ilkay Demir, Yusuf Koçak, A. Emre Kasapoğlu, Manijeh Razeghi, Emre Gür and Sezai Elagoz Semicond. Sci. Technol. 34 075028-- June 24, 2019 ...[Visit Journal] We report a new growth approach pulsed co-doping growth of Al_xGa_1−xN (x > 0.5) epilayers on AlN/Al₂O₃ templates by metal organic vapor phase epitaxy (MOVPE). Using this approach SiH₄ (silane) and TMIn (trimethylindium) supplied to the growth chamber alternately and pulsed during the growth of AlGaN epilayers. Structural and morphological quality of AlGaN epilayers were investigated by high resolution x-ray diffraction (HR-XRD), atomic force microscopy (AFM), Raman spectroscopy, and scanning electron microscopy (SEM) techniques. It has shown that higher crystalline quality with low full width at half maximum (FWHM) and smoother surface morphology with reduced hexagonal hillock density has been obtained by the pulsed co-doping growth approach. Volcano like hillock structures has been confirmed by Raman mapping. [reprint (PDF)]
18.	Combined resonant tunneling and rate equation modeling of terahertz quantum cascade lasers Zhichao Chen , Andong Liu, Dong Chang , Sukhdeep Dhillon , Manijeh Razeghi , Feihu Wang Journal of Applied Physics, 135, 115703 ...[Visit Journal] Terahertz (THz) quantum cascade lasers (QCLs) are technologically important laser sources for the THz range but are complex to model. An efficient extended rate equation model is developed here by incorporating the resonant tunneling mechanism from the density matrix formalism, which permits to simulate THz QCLs with thick carrier injection barriers within the semi-classical formalism. A self-consistent solution is obtained by iteratively solving the Schrödinger-Poisson equation with this transport model. Carrier-light coupling is also included to simulate the current behavior arising from stimulated emission. As a quasi-ab initio model, intermediate parameters such as pure dephasing time and optical linewidth are dynamically calculated in the convergence process, and the only fitting parameters are the interface roughness correlation length and height. Good agreement has been achieved by comparing the simulation results of various designs with experiments, and other models such as density matrix Monte Carlo and non-equilibrium Green’s function method that, unlike here, require important computational resources. The accuracy, compatibility, and computational efficiency of our model enables many application scenarios, such as design optimization and quantitative insights into THz QCLs. Finally, the source code of the model is also provided in the supplementary material of this article for readers to repeat the results presented here, investigate and optimize new designs. [reprint (PDF)]
18.	High Power 3-12 μm Infrared Lasers: Recent Improvements and Future Trends M. Razeghi, S. Slivken, A. Tahraoui, A. Matlis, and Y.S. Park Physica E: Low-Dimensional Systems and Nanostructures 11 (2-3)-- October 1, 2001 ...[Visit Journal] In this paper, we discuss the progress of quantum cascade lasers (QCLs) grown by gas-source molecular beam epitaxy. Room temperature QCL operation has been reported for lasers emitting between 5-11 μm, with 9-11 μm lasers operating up to 425 K. Laser technology for the 3-5 μm range takes advantage of a strain-balanced active layer design. We also demonstrate record room temperature peak output powers at 9 and 11 μm (2.5 and 1 W, respectively) as well as record low 80K threshold current densities (250 A/cm²) for some laser designs. Preliminary distributed feedback (DFB) results are also presented and exhibit single mode operation for 9 μm lasers at room temperature. [reprint (PDF)]
18.	First cw operation of a Ga0.25In0.75As0.5P0.5‐InP laser on a silicon substrate M. Razeghi; M. Defour; R. Blondeau; F. Omnes; P. Maurel; O. Acher; F. Brillouet; J. C. C‐Fan; J. Salerno Appl. Phys. Lett. 53, 2389–2390 (1988) -- December 12, 1988 ...[Visit Journal] We report the first successful room-temperature cw operations of a GaO. 25 1110.75 ASo. 5 po. s -InP buried ridge structure laser emitting at 1.3 f-tm grown by two-step low-pressure metalorganic chemical vapor deposition on a silicon substrate. An output power of 20 m W with an external quantum efficiency of 16% at room temperature has been obtained. A threshold current as low as 45 rnA under cw operation at room temperature has been measured. The first cw aging test at room temperature, at 2 mW during 5 h, shows a very low degradation (Ill 11,;;5%). [reprint (PDF)]
18.	Scaling in back-illuminated GaN avalanche photodiodes K. Minder, J.L. Pau, R. McClintock, P. Kung, C. Bayram, M. Razeghi and D. Silversmith Applied Physics Letters, Vol. 91, No. 7, p. 073513-1-- August 13, 2007 ...[Visit Journal] Avalanche p-i-n photodiodes of various mesa areas were fabricated on AlN templates for back illumination for enhanced performance through hole-initiated multiplication, and the effects of increased area on device performance were studied. Avalanche multiplication was observed in mesa sizes up to 14,063 µm^2 under linear mode operation. Uniform gain and a linear increase of the dark current with area were demonstrated. [reprint (PDF)]
18.	On the performance and surface passivation of type-II InAs/GaSb superlattice photodiodes for the very-long- wavelength infrared A. Hood, M. Razeghi, E. Aifer, G.J. Brown Applied Physics Letters 87 (1)-- October 10, 2005 ...[Visit Journal] We demonstrate very-long-wavelength infrared Type-II InAs/GaSb superlattice photodiodes with a cutoff wavelength (λ_c,50%) of 17 μm. We observed a zero-bias, peak Johnson noise-limited detectivity of 7.63×10⁹ cm·Hz^½/W at 77 K with a 90%-10% cutoff width of 17 meV, and quantum efficiency of 30%. Variable area diode zero-bias resistance-area product (R₀A) measurements indicated that silicon dioxide passivation increased surface resistivity by nearly a factor of 5, over unpassivated photodiodes, and increased overall R₀A uniformity. The bulk R₀A at 77 K was found to be 0.08 Ω·cm², with RA increasing more than twofold at 25 mV reverse bias. [reprint (PDF)]
18.	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)]
18.	High performance focal plane array based on type-II InAs/GaSb superlattice heterostructures P.Y. Delaunay and M. Razeghi SPIE Conference, January 20-25, 2008, San Jose, CA Proceedings – Quantum Sensing and Nanophotonic Devices V, Vol. 6900, p. 69000M-1-10.-- February 1, 2008 ...[Visit Journal] Recent progress in growth techniques, structure design and processing has lifted the performances of Type-II InAs/GaSb superlattice photodetectors. A double heterostructure design, based on a low band gap (11 µm) active region and high band gap (5 µm) superlattice contacts, reduced the sensitivity of the superlattice to surface effects. The heterodiodes with an 11 µm cutoff, passivated with SiO₂, presented similar performances to unpassivated devices and a one order of magnitude increase of the resistivity of the sidewalls, even after flip-chip bonding and underfill. Thanks to this new design and to the inversion of the polarity of the devices, a high performance focal plane array with an 11 µm cutoff was demonstrated. The noise equivalent temperature difference was measured as 26 mK and 19 mK for operating temperatures of 81 K and 67 K. At an integration time of 0.08 ms, the FPA presented a quantum efficiency superior to 50%. [reprint (PDF)]

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