Center for Quantum Devices - Most Downloaded Journal Articles

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16.	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)]
16.	Temperature dependence of the quantized Hall effect H. P. Wei, A. M. Chang, and D. C. Tsui M. Razeghi Phys. Rev. B 32, 7016(R) 1985-- November 15, 1985 ...[Visit Journal] We reported detailed measurements of the temperature dependence of the quantized Hall effect from 4.2 to 50 K in the i=2 plateau region in InGaAs-InP. We deduce from the data that there is a significant density of localized states between the two Landau levels, with a value of ∼1×1010 cm−2 meV−1 at the middle of the mobility gap. We also found that the correlations between 𝜎xx and 𝜎xy show the trend predicted by the recent two-parameter scaling theory of localization in quantized Hall effect. [reprint (PDF)]
16.	High power, high wall-plug efficiency, high reliability, continuous-wave operation quantum cascade lasers at Center for Quantum Devices Razeghi, Manijeh SPIE Proceedings Volume 11296, Optical, Opto-Atomic, and Entanglement-Enhanced Precision Metrology II; 112961C-- February 25, 2020 ...[Visit Journal] Since the demonstration of the first quantum cascade laser (QCL) in 1997, QCLs have undergone considerable developments in output power, wall plug efficiency (WPE), beam quality, wavelength coverage and tunability. Among them, many world-class breakthroughs were achieved at the Center for Quantum Device at Northwestern University. In this paper, we will discuss the recent progress of our research and present the main contributions of the Center for Quantum Devices to the QCL family on high power, high wall-plug efficiency (WPE), continuous-wave (CW) and room temperature operation lasers. [reprint (PDF)]
16.	GaInAs and GaInAsP materials grown by low pressure MOCVD for microwave and optoelectronic applications J.P. Duchemin, J.P. Hirtz, M. Razeghi, M. Bonnet , S.D. Hersee J.P. Duchemin, J.P. Hirtz, M. Razeghi, M. Bonnet, S.D. Hersee, GaInAs and GaInAsP materials grown by low pressure MOCVD for microwave and optoelectronic applications, Journal of Crystal Growth, Volume 55, Issue 1, 1981, Pages 64-73-- October 1, 1981 ...[Visit Journal] The low pressure MOCVD technique has been successfully used to grow GaInAsP, lattice-matched to InP, for the complete compositional range between InP (λ=0.91 μm) and the ternary compound Ga0.47In0.53As (λ=1.67 μm). By contrast to LPE growth it has been found that during the MOCVD growth of double heterostructures InP can be grown directly onto the ternary or quaternary with no disturbance of the active layer, i.e. there is no effect equivalent to “melt back”. The compositional grading on both sides of the active layer was measured by scanning Auger spectroscopy on bevelled samples. It was found that the graded regions were typically less than 100 Å wide for GaInAsP active layers and less than 50 Å wide for GaInAs active layers. Single layers of undoped GaInAs exhibited a typical mobility of 6700 cm2 V-1s-1 at 1.5×1017 cm-3. The compositional uniformity of the ternary layers was characterised by measurement of the photoluminescence wavelength at various points on a large sample. The wavelength varied by <3 nm over 95% of the area, which was approximately 8 cm2. Our early MOCVD grown GaInAsP/InP DH lasers exhibited high thresholds due to a poor interface between the p-InP and the active layer. However, recently fabricated broad area lasers emitting at 1.27 μm show an average threshold current density of 1.5 kA cm-2 with a T0 of between 70 to 80 K. Stripe geometry lasers have being fabricated from this material and CW operation has been obtained. [reprint (PDF)]
16.	Al_xGa_1−xN-based solar-blind ultraviolet photodetector based on lateral epitaxial overgrowth of AlN on Si substrate E. Cicek, R. McClintock, C. Y. Cho, B. Rahnema, and M. Razeghi Appl. Phys. Lett. 103, 181113 (2013)-- October 30, 2013 ...[Visit Journal] We report on Al_xGa_1−xN-based solar-blind ultraviolet (UV) photodetector (PD) grown on Si(111) substrate. First, Si(111) substrate is patterned, and then metalorganic chemical vapor deposition is implemented for a fully-coalesced ∼8.5 μm AlN template layer via a pulsed atomic layer epitaxial growth technique. A back-illuminated p-i-n PD structure is subsequently grown on the high quality AlN template layer. After processing and implementation of Si(111) substrate removal, the optical and electrical characteristic of PDs are studied. Solar-blind operation is observed throughout the array; at the peak detection wavelength of 290 nm, 625 μm² area PD showed unbiased peak external quantum efficiency and responsivity of ∼7% and 18.3 mA/W, respectively, with a UV and visible rejection ratio of more than three orders of magnitude. Electrical measurements yielded a low-dark current density below 1.6 × 10⁻⁸ A/cm² at 10 V reverse bias. [reprint (PDF)]
16.	Kinetics of photoconductivity in n-type GaN photodetector P. Kung, X. Zhang, D. Walker, A. Saxler, J. Piotrowski, A. Rogalski, and M. Razeghi Applied Physics Letters 67 (25)-- December 18, 1995 ...[Visit Journal] High-quality ultraviolet photoconductive detectors have been fabricated using GaN layers grown by low-pressure metalorganic chemical vapor deposition on (11⋅0) sapphire substrates. The spectral responsivity remained nearly constant for wavelengths from 200 to 365 nm and dropped sharply by almost three orders of magnitude for wavelengths longer than 365 nm. The kinetics of the photoconductivity have been studied by the measurements of the frequency‐dependent photoresponse and photoconductivity decay. Strongly sublinear response and excitation‐dependent response time have been observed even at relatively low excitation levels. This can be attributed to redistribution of the charge carriers with increased excitation level. [reprint (PDF)]
16.	Reliable High-Power Uncoated Al-free InGaAsP/GaAs Lasers for Cost-Sensitive Optical Communication and Processing Applications M. Razeghi SPIE Conference, Dallas, TX, -- November 4, 1997 ...[Visit Journal] Unlike InP-based systems for long-distance communication applications, GaAs-based optoelectronic systems mostly for local-area network, optical interconnection or optical computing are very cost-sensitive because often these optoelectronic devices constitute most of the cost for these applications and fewer users share the cost. Thus besides technical issues, the processing cost should be addressed in the selection of materials and fabrication methods. We discuss a number of major advantages of Al-free InGaAsP/GaAs lasers for these applications, such as not coating- requirement, low cost, high long-term reliability, high performance. We discuss recent preliminary results of Al- free lasers as a first step toward these optoelectronic applications. [reprint (PDF)]
16.	Negative luminescence of long-wavelength InAs/GaSb superlattice photodiodes D. Hoffman, A. Hood, Y. Wei, A. Gin, F. Fuchs, and M. Razeghi Applied Physics Letters 87 (20)-- November 14, 2005 ...[Visit Journal] The electrically pumped emission behavior of binary type-II InAs/GaSb superlattice photodiodes has been studied in the spectral range between 8 µm and 13 µm. With a radiometric calibration of the experimental setup, the internal and external quantum efficiency has been determined in the temperature range between 80 K and 300 K for both, the negative and positive luminescence. The negative luminescence efficiency approaches values as high as 35% without antireflection coating. The temperature dependence of the internal quantum efficiency near zero-bias voltage allows for the determination of the electron-hole-electron Auger recombination coefficient of Γ_n=1×10²⁴ cm⁶ s^–1. [reprint (PDF)]
16.	Advances in APDs for UV astronomy Melville P. Ulmer; Ryan M. McClintock; Jose L. Pau; Manijeh Razeghi Proc. SPIE 6686, UV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XV, 668605 (September 13, 2007)-- November 13, 2007 ...[Visit Journal] We report the most recent work of our group of the development of avalanche photo diodes based on (Al)GaN. The goal of this group is to achieve single photon counting. In this paper we first give the scientific motivation for making such a device in the context of UV astronomy and then describe current work and plans for future development. The development includes improving the sensitivity to be able to carry out single photon detection and the fabrication of arrays. [reprint (PDF)]
16.	Investigations on the substrate dependence of the properties in nominally-undoped β-Ga2O3 thin films grown by PLD F. H. Teherani ; D. J. Rogers ; V. E. Sandana ; P. Bove ; C. Ton-That ; L. L. C. Lem ; E. Chikoidze ; M. Neumann-Spallart ; Y. Dumont ; T. Huynh ; M. R. Phillips ; P. Chapon ; R. McClintock ; M. Razeghi Proc. SPIE 10105, Oxide-based Materials and Devices VIII, 101051R-OLD-- March 23, 2017 ...[Visit Journal] Nominally-undoped Ga₂O₃ layers were deposited on a-, c- and r-plane sapphire substrates using pulsed laser deposition. Conventional x-ray diffraction analysis for films grown on a- and c-plane sapphire showed the layers to be in the β-Ga₂O₃ phase with preferential orientation of the (-201) axis along the growth direction. Pole figures revealed the film grown on r-plane sapphire to also be in the β-Ga₂O₃ phase but with epitaxial offsets of 29.5°, 38.5° and 64° from the growth direction for the (-201) axis. Optical transmission spectroscopy indicated that the bandgap was ~5.2eV, for all the layers and that the transparency was > 80% in the visible wavelength range. Four point collinear resistivity and Van der Pauw based Hall measurements revealed the β-Ga₂O₃ layer on r-plane sapphire to be 4 orders of magnitude more conducting than layers grown on a- and c-plane sapphire under similar conditions. The absolute values of conductivity, carrier mobility and carrier concentration for the β-Ga₂O₃ layer on r-sapphire (at 20Ω-1.cm^-1, 6 cm²/Vs and 1.7 x 10¹⁹ cm^-3, respectively) all exceeded values found in the literature for nominally-undoped β-Ga₂O₃ thin films by at least an order of magnitude. Gas discharge optical emission spectroscopy compositional depth profiling for common shallow donor impurities (Cl, F, Si and Sn) did not indicate any discernable increase in their concentrations compared to background levels in the sapphire substrate. It is proposed that the fundamentally anisotropic conductivity in β-Ga₂O₃ combined with the epitaxial offset of the (-201) axis observed for the layer grown on r-plane sapphire may explain the much larger carrier concentration, electrical conductivity and mobility compared with layers having the (-201) axis aligned along the growth direction. [reprint (PDF)]
16.	Quantum Dot Infrared Photodetectors: Comparison Experiment and Theory H. Lim, W. Zhang, S. Tsao, T. Sills, J. Szafraniec, K. Mi, B. Movaghar, and M. Razeghi Physical Review B, 72-- August 17, 2005 ...[Visit Journal] We present data and calculations and examine the factors that determine the detectivities in self-assembled InAs and InGaAs based quantum dot infrared photodetectors (QDIPs). We investigate a class of devices that combine good wavelength selectivity with “high detectivity.” We study the factors that limit the temperature performance of quantum dot detectors. For this we develop a formalism to evaluate the optical absorption and the electron transport properties. We examine the performance limiting factors and compare theory with experimental data. We find that the notion of a phonon bottleneck does not apply to large-diameter lenslike quantum dots, which have many closely spaced energy levels. The observed strong decrease of responsivity with temperature is ultimately due to a rapid thermal cascade back into the ground states. High temperature performance is improved by engineering the excited state to be near the continuum. The good low temperature (77 K) performance in strongly bound QDIPs is shown to be due to the high gain and the low noise achievable in these micron size devices. [reprint (PDF)]
16.	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)]
15.	Room temperature continuous wave THz frequency comb based on quantum cascade lasers M. Razeghi; Q. Y. Lu; F. H. Wang; D. H. Wu; S. Slivken Proc. SPIE 11124, Terahertz Emitters, Receivers, and Applications X, 1112407-- September 6, 2019 ...[Visit Journal] Frequency combs, spectra of phase-coherent equidistant lines, have revolutionized time and frequency metrology. The recently developed quantum cascade laser (QCL) comb has exhibits great potential with high power and broadband spectrum. However, in the terahertz (THz) range, cryogenic cooling has to be applied for THz QCL combs. We report a room temperature THz frequency comb at 3.0 THz based on difference-frequency generation from a mid-IR QCL comb. A largely detuned distributed-feedback grating is integrated into the QCL cavity to provide the single mode operation as well as enhanced spatial hole-burning effect for multimode comb operation. Multiheterodyne spectroscopy with multiple equally spaced lines by beating it with a reference Fabry-Pérot comb confirms the THz comb operation. This type of THz comb provides a new solution to chip-based high-speed high-resolution THz spectroscopy with compact size at room temperature. [reprint (PDF)]
15.	Molecular Beam Epitaxial Growth of High Quality InSb E. Michel, G. Singh, S. Slivken, C. Besikci, P. Bove, I. Ferguson, and M. Razeghi Applied Physics Letters 65 (26)-- December 26, 1994 ...[Visit Journal] In this letter we report on the growth of high quality InSb by molecular beam epitaxy that has been optimized using reflection high energy electron diffraction. A 4.8 µm InSb layer grown on GaAs at a growth temperature of 395 °C and a III/V incorporation ratio of 1:1.2 had an x-ray rocking curve of 158 arcsec and a Hall mobility of 92,300 cm²·V⁻¹ at 77 K. This is the best material quality obtained for InSb nucleated directly onto GaAs reported to date. [reprint (PDF)]
15.	Demonstration of mid-wavelength infrared nBn photodetectors based on type-II InAs/InAs_1-xSb_x superlattice grown by metal-organic chemical vapor deposition Donghai Wu, Arash Dehzangi, and Manijeh Razeghi Appl. Phys. Lett. 115, 061102-- August 6, 2019 ...[Visit Journal] We report design, growth, and characterization of midwavelength infrared nBn photodetectors based on a type-II InAs/InAs_1-xSb_x superlattice on a GaSb substrate grown by metal-organic chemical vapor deposition. An InAs/AlAs_1-ySb_y/InAs/InAs_1-xSb_x superlattice design was used as the large bandgap electron barrier in the photodetectors. At 150 K, the photodetector exhibits a peak responsivity of 1.23 A/W, corresponding to a quantum efficiency of 41% at an applied bias voltage of −100 mV under front-side illumination, with a 50% cut-off wavelength of 4.6 μm. With an R × A of 356 Ω·cm² and a dark current density of 1.6 × 10⁻⁴ A/cm² under an applied bias of −100 mV at 150 K, the photodetector exhibits a specific detectivity of 1.4 × 10¹¹ cm·Hz^1/2/W. [reprint (PDF)]
15.	Use of PLD-grown moth-eye ZnO nanostructures as templates for MOVPE growth of InGaN-based photovoltaics Dave Rogers, V. E. Sandana, F. Hosseini Teherani, S. Gautier, G. Orsal, T. Moudakir, M. Molinari, M. Troyon, M. Peres, M. J. Soares, A. J. Neves, T. Monteiro, D. McGrouther, J. N. Chapman, H. J. Drouhin, M. Razeghi, and A. Ougazzaden Renewable Energy and the Environment, OSA Technical Digest paper PWB3, Optical Society of America, (2011)-- November 2, 2011 ...[Visit Journal] At this time, no abstract is available. Scopus has content delivery agreements in place with each publisher and currently contains 30 million records with an abstract. An abstract may not be present due to incomplete data, as supplied by the publisher, or is still in the process of being indexed. [reprint (PDF)]
15.	The correlation between x-ray diffraction patterns and strain distribution inside GaInP/GaAs superlattices X.G. He, M. Erdtmann, R. Williams, S. Kim, and M. Razeghi Applied Physics Letters 65 (22)-- November 28, 1994 ...[Visit Journal] Strong correlation between x‐ray diffraction characteristics and strain distribution inside GaInP/GaAs superlattices has been reported. It is found that the symmetry of (002) diffraction patterns can be used to evaluate the interface strain status. A sample with no interfacial strains has a symmetric (002) diffraction pattern and weak (004) diffraction pattern. It is also demonstrated that strain distribution in superlattices can be readily estimated qualitatively by analyzing x-ray diffraction patterns. [reprint (PDF)]
15.	High performance mid-wavelength quantum dot infrared photodetectors for focal plane arrays M. Razeghi, H. Lim, S. Tsao, M. Taguchi, W. Zhang and A.A. Quivy SPIE Conference, San Diego, CA, Vol. 6297, pp. 62970C-- August 13, 2006 ...[Visit Journal] Quantum dot infrared photodetectors (QDIPs) have recently emerged as promising candidates for detection in the middle wavelength infrared (MWIR) and long wavelength infrared (LWIR) ranges. Here, we report our recent results for mid-wavelength QDIPs grown by low-pressure metalorganic chemical vapor deposition. Three monolayer of In_0.68Ga_0.32As self-assembled via the Stranski-Krastanov growth mode and formed lens-shaped InGaAs quantum dots with a density around 3×10₁₀ cm^-2. The peak responsivity at 77 K was measured to be 3.4 A/W at a bias of -1.9 V with 4.7 µm peak detection wavelength. Focal plane arrays (FPAs) based on these devices have been developed. The preliminary result of FPA imaging is presented. [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.	Metalorganic chemical vapor deposition of monocrystalline GaN thin films on β-LiGaO2substrates P. Kung, A. Saxler, X. Zhang, D. Walker, R. Lavado, and M. Razeghi Applied Physics Letters 69 (14)-- September 30, 1996 ...[Visit Journal] We report the metalorganic chemical vapor deposition growth and characterization of monocrystalline GaN thin films on β-LiGaO₂ substrates. The influence of the growth temperature on the crystal quality was studied. The structural, electrical, and optical properties of the films were assessed through scanning electron microscopy, x-ray diffraction, Hall measurements, optical transmission, photoluminescence. [reprint (PDF)]
15.	Thin-Film Antimonide-Based Photodetectors Integrated on Si Yiyun Zhang , Member, IEEE, Abbas Haddadi, Member, IEEE, Romain Chevallier, Arash Dehzangi, Member, IEEE, and Manijeh Razeghi , Life Fellow, IEEE IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 54, NO. 2-- April 1, 2018 ...[Visit Journal] Monolithic integration of antimonide (Sb)-based compound semiconductors on Si is in high demand to enrich silicon photonics by extending the detection range to longer infrared wavelengths. In this paper, we have demonstrated the damage-free transfer of large-area (1×1 cm² ) narrow-bandgap Sb-based type-II superlattice (T2SL)-based thin-film materials onto a Si substrate using a combination of wafer-bonding and chemical epilayer release techniques. An array of Sb-based T2SL-based long-wavelength infrared (LWIR) photodetectors with diameters from 100 to 400 μm has been successfully fabricated using standard "top–down" processing technique. The transferred LWIR photodetectors exhibit a cut-off wavelength of λ 8.6 μm at 77 K. The dark current density of the transferred photodetectors under 200 mV applied bias at 77 K is as low as 5.7×10⁻⁴ A/cm² and the R×A reaches 66.3 Ω·cm², exhibiting no electrical degradation compared with reference samples on GaSb native substrate. The quantum efficiency and peak responsivity at 6.75 μm (@77 K, 200 mV) are 46.2% and 2.44 A/W, respectively. The specific detectivity (D^*) at 6.75 μm reaches as high as 1.6×10¹¹ cm·Hz^1/2/W under 200 mV bias at 77 K. Our method opens a reliable pathway to realize high performance and practical Sb-based optoelectronic devices on a Si platform. [reprint (PDF)]
15.	Stable single mode terahertz semiconductor sources at room temperature M. Razeghi 2011 International Semiconductor Device Research Symposium, ISDRS [6135180] (2011).-- December 7, 2011 ...[Visit Journal] Terahertz (THz) range is an area of the electromagnetic spectra which has lots of applications but it suffers from the lack of simple working devices which can emit THz radiation, such as the high performance mid-infrared (mid-IR) quantum cascade lasers (QCLs) based on InP technology. The applications for the THz can be found in astronomy and space research, biology imaging, security, industrial inspection, etc. Unlike THz QCLs based on the fundamental oscillators, which are limited to cryogenic operations, semiconductor THz sources based on nonlinear effects of mid-IR QCLs do not suffer from operating temperature limitations, because mid-IR QCLs can operate well above room temperature. THz sources based on difference frequency generation (DFG) utilize nonlinear properties of asymmetric quantum structures, such as QCL structures. [reprint (PDF)]
15.	Spatial Noise and Correctability of Type-II InAs/GaSb Focal Plane Arrays P.Y. Delaunay and M. Razeghi IEEE Journal of Quanutm Electronics, April 2010, Vol. 46, No. 4, p. 584-588-- April 1, 2010 ...[Visit Journal] A long wavelength infrared focal plane array based on Type-II InAs/GaSb superlattices was fabricated and characterized at 80 K. The noise equivalent temperature difference of the array was measured as low as 23 mK (f# = 2), for an integration time of 0.129 ms. The spatial noise of the array was dominated by the nonuniformity of the illumination through the circular aperture. A standard two-point nonuniformity correction improved the inhomogeneity equivalent temperature difference to 16 mK. The correctability just after calibration was 0.6. The long-term stability time was superior to 25 hours. [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.	Monolithic Integration of GaInAs/InP Quantum Well Infrared Photodetectors on Si Substrate M. Erdtmann and M. Razeghi SPIE Conference, San Jose, CA, -- January 22, 2001 ...[Visit Journal] Using low-pressure metalorganic chemical vapor deposition, we have grown GaInAs/InP QWIP structures on GaAs-coated Si substrate. First, the procedure to optimize the epitaxy of the InP buffer layer on Si substrate is given. Excellent crystallinity and a mirror-like surface morphology were obtained by using both a two-step growth process at the beginning of the InP buffer layer growth and several series of thermal cycle annealing throughout the InP buffer layer growth. Second, results of fabricated GaInAs/InP QWIPs on Si substrate are presented. At a temperature of 80 K, the peak response wavelength occurs at 7.4 μm. The responsivities of QWIPs on both Si and InP substrates with identical structures are equal up to biases of 1.5 V. At a bias of 3 V, the responsivity of the QWIPs on Si substrate is 1.0 A/W. [reprint (PDF)]

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