The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Manijeh Razeghi - One of the best experts on this subject based on the ideXlab platform.
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high performance focal plane array based on inas gasb superlattices with a 10 mu hbox m Cutoff Wavelength
IEEE Journal of Quantum Electronics, 2008Co-Authors: Pierreyves Delaunay, Binhminh Nguyen, Darin Hoffman, Manijeh RazeghiAbstract: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 mum. 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 Omegamiddotcm2 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.
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very high quantum efficiency in type ii inas gasb superlattice photodiode with Cutoff of 12 μm
Applied Physics Letters, 2007Co-Authors: Binhminh Nguyen, Pierreyves Delaunay, Darin Hoffman, Andrew Hood, Manijeh RazeghiAbstract:The authors report the dependence of the quantum efficiency on device thickness of type-II InAs∕GaSb superlattice photodetectors with a Cutoff Wavelength around 12μm. The quantum efficiency and responsivity show a clear delineation in comparison to the device thickness. An external single-pass quantum efficiency of 54% is obtained for a 12μm Cutoff Wavelength photodiodes with a π-region thickness of 6.0μm. The R0A value is kept stable for the range of structure thicknesses allowing for a specific detectivity (2.2×1011cmHz∕W).
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320 256 infrared focal plane array based on type ii inas gasb superlattice with a 12 μm Cutoff Wavelength
Infrared Technology and Applications XXXIII, 2007Co-Authors: Pierreyves Delaunay, Binhminh Nguyen, Darin Hoffman, Manijeh RazeghiAbstract: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 mm. Electrical and optical measurements performed on single element detectors at 77 K showed an R0A averaging 13 O.cm 2 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 A over an area of 20x20 mm 2 . A 320x256 array of 25x25mm 2 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.
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high differential resistance type ii inas gasb superlattice photodiodes for the long Wavelength infrared
Applied Physics Letters, 2006Co-Authors: Andrew Hood, Pierreyves Delaunay, Binhminh Nguyen, Darin Hoffman, E Michel, Manijeh RazeghiAbstract:Type-II InAs∕GaSb superlattice photodiodes with a 50% Cutoff Wavelength ranging from 11to13μm are presented. Optimization of diffusion limited photodiodes provided superlattice structures for improved injection efficiency in direct injection hybrid focal plane array applications. Photodiodes with a Cutoff Wavelength of 12.9μm exhibit an R0A of ∼7Ωcm2 and a Johnson-limited detectivity of 4.03×1010cmHz1∕2W−1 operating at 77K. Quantum efficiency measurements indicate minority carrier diffusion lengths exceeding 3μm.
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high performance type ii inas gasb superlattice photodiodes with Cutoff Wavelength around 7 μm
Applied Physics Letters, 2005Co-Authors: Yajun Wei, Manijeh Razeghi, Andrew Hood, H Yau, V R Yazdanpanah, Meimei Z Tidrow, Vaidya NathanAbstract:We report the most recent result in the area of type-II InAs/GaSb superlattice photodiodes that have a Cutoff Wavelength around 7 μm at 77 K. Superlattice with a period of 40 A lattice matched to GaSb was realized using GaxIn1−x type interface engineering technique. Compared with significantly longer period superlattices, we have reduced the dark current density under reverse bias dramatically. For a 3 μm thick structure, using sulfide-based passivation, the dark current density reached 2.6×10−5A∕cm2 at −3 V reverse bias at 77 K. At this temperature the photodiodes have R0A of 9300Ωcm2 and a thermally limited zero bias detectivity of 1×1012cmHz1∕2∕W. The 90%–10% Cutoff energy width was only 16.5 meV. The devices did not show significant dark current change at 77 K after three months storage in the atmosphere.
Gail J Brown - One of the best experts on this subject based on the ideXlab platform.
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optimizing residual carriers in undoped inas gasb superlattices for high operating temperature mid infrared detectors
Journal of Crystal Growth, 2009Co-Authors: H J Haugan, S Elhamri, Bruno Ullrich, Frank Szmulowicz, Gail J Brown, W C MitchelAbstract:The mid-infrared 21 A InAs/24 A GaSb superlattices (SLs) designed for the 4 μm Cutoff Wavelength were grown by molecular beam epitaxy at growth temperatures between 370 and 430 °C in order to reduce residual background carriers. The lowest density of 1.8 × 10 11 cm -2 was obtained from the SLs grown at 400 °C. With increasing growth temperature, in-plane hole mobility decreased from 8740 to 1400 cm 2 / Vs due to increased interfacial roughness, while the photoluminescence (PL) intensity increased due to a decrease in the number of nonstoichiometric nonradiative defects. Further reduction of carrier density to 1 × 10 11 cm -2 was achieved by increasing barrier width. As GaSb layer width increases from 24 to 48 A, the Cutoff Wavelength decreased from 4.1 to 3.4 μm, which is still in the mid-infrared detection window. More importantly, a dramatic improvement on the PL intensity and the full width at half maximum was achieved from the SL samples with the wider GaSb widths. All mid-infrared SL samples investigated in our studies were residually p-type.
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high quality type ii inas gasb superlattices with Cutoff Wavelength 3 7 μm using interface engineering
Journal of Applied Physics, 2003Co-Authors: Yajun Wei, Gail J Brown, Manijeh Razeghi, Andrew Hood, Junjik Bae, Aaron Gin, Meimei Z TidrowAbstract:We report the most recent advance in the area of type II InAs/GaSb superlattices that have Cutoff Wavelength of ∼3.7 μm. With GaxIn1−x type interface engineering techniques, the mismatch between the superlattices and the GaSb (001) substrate has been reduced to <0.1%. There is no evidence of dislocations using the best examination tools of x-ray, atomic force microscopy, and transmission electron microscopy. The full width half maximum of the photoluminescence peak at 11 K was ∼4.5 meV using an Ar+ ion laser (514 nm) at fluent power of 140 mW. The integrated photoluminescence intensity was linearly dependent on the fluent laser power from 2.2 to 140 mW at 11 K. The temperature-dependent photoluminescence measurement revealed a characteristic temperature of one T1=245 K at sample temperatures below 160 K with fluent power of 70 mW, and T1=203 K for sample temperatures above 180 K with fluent power of 70 and 420 mW.
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type ii inas gasb superlattice photovoltaic detectors with Cutoff Wavelength approaching 32 μm
Applied Physics Letters, 2002Co-Authors: Manijeh Razeghi, Gail J BrownAbstract:We report the most recent advance in the area of type II InAs/GaSb superlattice photovoltaic detectors that have Cutoff Wavelengths beyond 25 μm, with some at nearly 32 μm. The photodiodes with a heterosuperlattice junction showed Johnson noise limited peak detectivity of 1.05×1010 cm Hz1/2/W at 15 μm under zero bias, and peak responsivity of 3 A/W under −40 mV reverse bias at 34 K illuminated by ∼300 K background with a 2π field-of-view. The maximum operating temperature of these detectors ranges from 50 to 65 K. No detectable change in the blackbody response has been observed after 5–6 thermal cyclings, with temperature varying between 15 and 296 K in vacuum.
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advanced inas gasb superlattice photovoltaic detectors for very long Wavelength infrared applications
Applied Physics Letters, 2002Co-Authors: Manijeh Razeghi, Gail J BrownAbstract:We report on the temperature dependence of the photoresponse of very long Wavelength infrared type-II InAs/GaSb superlattice based photovoltaic detectors grown by molecular-beam epitaxy. The detectors had a 50% Cutoff Wavelength of 18.8 μm and a peak current responsivity of 4 A/W at 80 K. A peak detectivity of 4.5×1010 cm Hz1/2/W was achieved at 80 K at a reverse bias of 110 mV. The generation–recombination lifetime was 0.4 ns at 80 K. The Cutoff Wavelength increased very slowly with increasing temperature with a net shift from 20 to 80 K of only 1.2 μm.
Andrew Hood - One of the best experts on this subject based on the ideXlab platform.
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very high quantum efficiency in type ii inas gasb superlattice photodiode with Cutoff of 12 μm
Applied Physics Letters, 2007Co-Authors: Binhminh Nguyen, Pierreyves Delaunay, Darin Hoffman, Andrew Hood, Manijeh RazeghiAbstract:The authors report the dependence of the quantum efficiency on device thickness of type-II InAs∕GaSb superlattice photodetectors with a Cutoff Wavelength around 12μm. The quantum efficiency and responsivity show a clear delineation in comparison to the device thickness. An external single-pass quantum efficiency of 54% is obtained for a 12μm Cutoff Wavelength photodiodes with a π-region thickness of 6.0μm. The R0A value is kept stable for the range of structure thicknesses allowing for a specific detectivity (2.2×1011cmHz∕W).
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high differential resistance type ii inas gasb superlattice photodiodes for the long Wavelength infrared
Applied Physics Letters, 2006Co-Authors: Andrew Hood, Pierreyves Delaunay, Binhminh Nguyen, Darin Hoffman, E Michel, Manijeh RazeghiAbstract:Type-II InAs∕GaSb superlattice photodiodes with a 50% Cutoff Wavelength ranging from 11to13μm are presented. Optimization of diffusion limited photodiodes provided superlattice structures for improved injection efficiency in direct injection hybrid focal plane array applications. Photodiodes with a Cutoff Wavelength of 12.9μm exhibit an R0A of ∼7Ωcm2 and a Johnson-limited detectivity of 4.03×1010cmHz1∕2W−1 operating at 77K. Quantum efficiency measurements indicate minority carrier diffusion lengths exceeding 3μm.
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high performance type ii inas gasb superlattice photodiodes with Cutoff Wavelength around 7 μm
Applied Physics Letters, 2005Co-Authors: Yajun Wei, Manijeh Razeghi, Andrew Hood, H Yau, V R Yazdanpanah, Meimei Z Tidrow, Vaidya NathanAbstract:We report the most recent result in the area of type-II InAs/GaSb superlattice photodiodes that have a Cutoff Wavelength around 7 μm at 77 K. Superlattice with a period of 40 A lattice matched to GaSb was realized using GaxIn1−x type interface engineering technique. Compared with significantly longer period superlattices, we have reduced the dark current density under reverse bias dramatically. For a 3 μm thick structure, using sulfide-based passivation, the dark current density reached 2.6×10−5A∕cm2 at −3 V reverse bias at 77 K. At this temperature the photodiodes have R0A of 9300Ωcm2 and a thermally limited zero bias detectivity of 1×1012cmHz1∕2∕W. The 90%–10% Cutoff energy width was only 16.5 meV. The devices did not show significant dark current change at 77 K after three months storage in the atmosphere.
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high quality type ii inas gasb superlattices with Cutoff Wavelength 3 7 μm using interface engineering
Journal of Applied Physics, 2003Co-Authors: Yajun Wei, Gail J Brown, Manijeh Razeghi, Andrew Hood, Junjik Bae, Aaron Gin, Meimei Z TidrowAbstract:We report the most recent advance in the area of type II InAs/GaSb superlattices that have Cutoff Wavelength of ∼3.7 μm. With GaxIn1−x type interface engineering techniques, the mismatch between the superlattices and the GaSb (001) substrate has been reduced to <0.1%. There is no evidence of dislocations using the best examination tools of x-ray, atomic force microscopy, and transmission electron microscopy. The full width half maximum of the photoluminescence peak at 11 K was ∼4.5 meV using an Ar+ ion laser (514 nm) at fluent power of 140 mW. The integrated photoluminescence intensity was linearly dependent on the fluent laser power from 2.2 to 140 mW at 11 K. The temperature-dependent photoluminescence measurement revealed a characteristic temperature of one T1=245 K at sample temperatures below 160 K with fluent power of 70 mW, and T1=203 K for sample temperatures above 180 K with fluent power of 70 and 420 mW.
Binhminh Nguyen - One of the best experts on this subject based on the ideXlab platform.
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high performance focal plane array based on inas gasb superlattices with a 10 mu hbox m Cutoff Wavelength
IEEE Journal of Quantum Electronics, 2008Co-Authors: Pierreyves Delaunay, Binhminh Nguyen, Darin Hoffman, Manijeh RazeghiAbstract: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 mum. 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 Omegamiddotcm2 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.
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very high quantum efficiency in type ii inas gasb superlattice photodiode with Cutoff of 12 μm
Applied Physics Letters, 2007Co-Authors: Binhminh Nguyen, Pierreyves Delaunay, Darin Hoffman, Andrew Hood, Manijeh RazeghiAbstract:The authors report the dependence of the quantum efficiency on device thickness of type-II InAs∕GaSb superlattice photodetectors with a Cutoff Wavelength around 12μm. The quantum efficiency and responsivity show a clear delineation in comparison to the device thickness. An external single-pass quantum efficiency of 54% is obtained for a 12μm Cutoff Wavelength photodiodes with a π-region thickness of 6.0μm. The R0A value is kept stable for the range of structure thicknesses allowing for a specific detectivity (2.2×1011cmHz∕W).
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320 256 infrared focal plane array based on type ii inas gasb superlattice with a 12 μm Cutoff Wavelength
Infrared Technology and Applications XXXIII, 2007Co-Authors: Pierreyves Delaunay, Binhminh Nguyen, Darin Hoffman, Manijeh RazeghiAbstract: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 mm. Electrical and optical measurements performed on single element detectors at 77 K showed an R0A averaging 13 O.cm 2 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 A over an area of 20x20 mm 2 . A 320x256 array of 25x25mm 2 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.
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high differential resistance type ii inas gasb superlattice photodiodes for the long Wavelength infrared
Applied Physics Letters, 2006Co-Authors: Andrew Hood, Pierreyves Delaunay, Binhminh Nguyen, Darin Hoffman, E Michel, Manijeh RazeghiAbstract:Type-II InAs∕GaSb superlattice photodiodes with a 50% Cutoff Wavelength ranging from 11to13μm are presented. Optimization of diffusion limited photodiodes provided superlattice structures for improved injection efficiency in direct injection hybrid focal plane array applications. Photodiodes with a Cutoff Wavelength of 12.9μm exhibit an R0A of ∼7Ωcm2 and a Johnson-limited detectivity of 4.03×1010cmHz1∕2W−1 operating at 77K. Quantum efficiency measurements indicate minority carrier diffusion lengths exceeding 3μm.
Guowei Wang - One of the best experts on this subject based on the ideXlab platform.
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growth and characterization of type ii superlattice photodiodes with Cutoff Wavelength of 12 μm on 4 in wafer
Optical and Quantum Electronics, 2019Co-Authors: Jie Guo, D S Jiang, Zhi Jiang, Guowei Wang, Ruiting Hao, Yu Liu, Faran Chang, Zhichuan NiuAbstract:High performance InAs/GaSb superlattices for long-Wavelength infrared detection were grown on a 4-in. GaSb wafer using molecular beam epitaxy. The influence of the growth temperature, V/III BEP ratio on the surface morphology and microstructure was researched. The good uniformity of the surface roughness and crystallization at four location along the radial direction on the wafer was obtained by balancing the inner and outer growth temperature. The performance deviation of the four photodiodes fabricated using the superlattices from center to edge on the wafer was below 20% which revealed the uniformity of the superlattice growth and the fabrication process. The 50% Cutoff Wavelength was about 12 μm. The peak responsivity was 2.54 A/W corresponding to a quantum efficiency of 35.1% at 77 K. The zero bias differential resistance-area product (R0A) was 2.1 Ω cm2 due to the barrier structure design which restrains the diffusion dark current. The calculated Johnson noise limited detectivity was 5.75 × 1010 cm √Hz/W at 10 μm and 4.13 × 1010 cm √Hz/W at 14 μm.
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significantly extended Cutoff Wavelength of very long wave infrared detectors based on inas gasb insb gasb superlattices
Applied Physics Letters, 2017Co-Authors: D S Jiang, Xi Han, Hongyue Hao, Yaoyao Sun, Zhi Jiang, Chunyan Guo, Guowei Wang, Zhichuan NiuAbstract:The authors report significant tunability of the bandgap in very long-wave infrared (VLWIR) InAs/GaSb/InSb/GaSb superlattices. Calculations using the empirical tight binding method have shown the flexibility in tuning the energy levels of the valence band by inserting a thin InSb layer in the middle of the GaSb layer of a normal type-II binary InAs/GaSb superlattice. Through the experimental realization of several barrier structure photodiodes with 15 ML InAs/7 ML GaSb active region, the Cutoff Wavelength was extended from 14.5 μm to 18.2 μm by inserting 0.6 ML InSb at different locations in GaSb layer. The agreement between the theoretical predictions and the experimental measurement suggests a way to exploit this advantage for the realization of very long-wave infrared detection without increasing the thickness of InAs layer. At 77 K, the quantum efficiency of a very long-wave detector with the Cutoff Wavelength of 16.9 μm reached at a maximum value of 30%, and the R0A is kept at a stable value of 10 Ω ...
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very high quantum efficiency in inas gasb superlattice for very long Wavelength detection with Cutoff of 21 μm
Applied Physics Letters, 2016Co-Authors: Dongwei Jiang, Xi Han, Hongyue Hao, Guowei Wang, Wei Xiang, Fengyun GuoAbstract:The authors report the dependence of the quantum efficiency on beryllium concentration in the active region of type-II InAs/GaSb superlattice infrared detector with a Cutoff Wavelength around 21 μm. It is found that the quantum efficiency and responsivity show a clear delineation in comparison to the doping concentration. The quantum efficiency is further improved by gradually doping in the absorbing region. At 77 K, the 50% Cutoff Wavelength of the VLWIR detector is 18 μm, and the R0A is kept at a stable value of 6 Ω cm2. Different beryllium concentration leads to an increase of an average quantum efficiency in the 8–15 μm window from 35% to 55% with a π-region thickness of 3.0 μm, for Ubias = −0.3 V, and no anti-reflection coating. As for a further result, the quantum efficiency reaches at a maximum value of 66% by gradually doping in the absorbing region with the peak detectivity of 3.33 × 1010 cm Hz1/2/W at 15 μm.
