Engineering topics
Ting, D. Z.
Publications and source records attributed to Ting, D. Z..
Extended Cut-Off Wavelength nBn Detector Utilizing InAsSb/InSb Digital Alloy Absorber
We investigated a novel approach to extend a cut -off wavelength of Sb-based nBn detectors. We incorporated a series of single InSb monolayer into InAsSb bulk that allowed to realize a digital alloy absorber with an extended cut-off wavelength of λ = 4.6 μm at T = 200 K. The cut-off wavelength extension to 4.6μm is technologically important for realization of detectors covering CO2 absorption line at 4.26μm
Band Engineering, Growth and Characteristics of Type-II InAs/GaSb Superlattice-Based Detectors
We report on band engineering, growth and device performance of infrared photodetectors based on type II InAs/Ga(In)Sb strain layer superlattices (SLs) using the complementary barrier infrared detector (CBIRD) design. The unipolar barriers on either side of the absorber in the CBIRD design in combination with the type-II InAs/GaSb superlattice material system are expected to outperform traditional III-V LWIR (Long-Wave InfraRed) imaging technologies and offer significant advantages over the conventional II-VI material based FPAs (Focal Plane Arrays). The innovative design of CBIRDS, barrier and band offset engineering , low defect density material growth, and robust fabrication processes have resulted in the development of high performance long wave infrared (LWIR) focal plane arrays at JPL (Jet Propulsion Laboratory).
Modulation Transfer Function of Infrared Focal Plane Arrays
Modulation transfer function (MTF) is the ability of an imaging system to faithfully image a given object. The MTF of an imaging system quantifies the ability of the system to resolve or transfer spatial frequencies. In this presentation we will discuss the detail MTF measurements of 1024x1024 pixels mid -wavelength and long- wavelength quantum well infrared photodetector, and 320x256 pixels long- wavelength InAs/GaSb superlattice infrared focal plane arrays (FPAs). Long wavelength Complementary Barrier Infrared Detector (CBIRD) based on InAs/GaSb superlattice material is hybridized to recently designed and fabricated 320x256 pixel format ROIC. The n-type CBIRD was characterized in terms of performance and thermal stability. The experimentally measured NE delta T of the 8.8 micron cutoff n-CBIRD FPA was 18.6 mK with 300 K background and f/2 cold stop at 78K FPA operating temperature. The horizontal and vertical MTFs of this pixel fully delineated CBIRD FPA at Nyquist frequency are 49% and 52%, respectively.
Superlattice Infrared Photodetector Research at the Jet Propulsion Laboratory
III-V semiconductors offer a highly effective platform for the development of sophisticated heterostructure-based MWIR and LWIR detectors, as exemplified by the high-performance double heterostructure (DH) nBn, XBn, and type- II superlattice infrared detectors. A key enabling design element is the unipolar barrier, which is used to implement the complementary barrier infra-red detector (CBIRD) design for increasing the collection efficiency of photo-generated carriers, and reducing dark current generation without impeding photocurrent flow. Heterostructure superlattice detectors that make effective use of unipolar barriers have demonstrated strong reduction of generation-recombination (G-R) dark current due to Shockley-Read-Hall (SRH) processes. In the last several years we solely focused on the development of antimonide based IR detectors. Recently, we demonstrated RoA values over 14,000 Ohm sq cm for a 9.9 micron cutoff device by incorporating electron-blocking and hole-blocking unipolar barriers. This device has shown 300K BLIP operation with f/2 optics at 87 K with blackbody D* of 1.1x10(exp 11) cm Hz1/2/W.
High performance GaSb/InAs superlattice long-wave infrared focal plane array
We describe the demonstration of a ¼ VGA format long-wavelength infrared focal plane array based on an InAs/GaSb superlattice absorber surrounded by an electron-blocking and a hole-blocking unipolar barrier. An 8.8 μm cutoff focal plane without antireflection coating based on this complementary barrier infrared detector design has yielded noise equivalent differential temperature of 18.6 mK at operating temperature of 80K, with 300 K background and f/2 cold-stop.
Thermal Imaging with Novel Infrared Focal Plane Arrays and Quantitative Analysis of Thermal Imagery
We have developed a single long-wavelength infrared (LWIR) quantum well infrared photodetector (QWIP) camera for thermography. This camera has been used to measure the temperature profile of patients. A pixel coregistered simultaneously reading mid-wavelength infrared (MWIR)/LWIR dual-band QWIP camera was developed to improve the accuracy of temperature measurements especially with objects with unknown emissivity. Even the dualband measurement can provide inaccurate results due to the fact that emissivity is a function of wavelength. Thus we have been developing a four-band QWIP camera for accurate temperature measurement of remote object.
Growth and Characteristics of Type-II InAs/GaSb Superlattice-Based Detectors
We report on growth and device performance of infrared photodetectors based on type II InAs/Ga(In)Sb strain layer superlattices (SLs) using the complementary barrier infrared detector (CBIRD) design. The unipolar barriers on either side of the absorber in the CBIRD design in combination with the type-II InAs/GaSb superlattice material system are expected to outperform traditional III-V LWIR imaging technologies and offer significant advantages over the conventional II-VI material based FPAs. The innovative design of CBIRDS, low defect density material growth, and robust fabrication processes have resulted in the development of high performance long wave infrared (LWIR) focal plane arrays at JPL.
III-V Infrared Research at the Jet Propulsion Laboratory
Jet Propulsion Laboratory is actively developing the III-V based infrared detector and focal plane arrays (FPAs) for NASA, DoD, and commercial applications. Currently, we are working on multi-band Quantum Well Infrared Photodetectors (QWIPs), Superlattice detectors, and Quantum Dot Infrared Photodetector (QDIPs) technologies suitable for high pixel-pixel uniformity and high pixel operability large area imaging arrays. In this paper we report the first demonstration of the megapixel-simultaneously-readable and pixel-co-registered dual-band QWIP focal plane array (FPA). In addition, we will present the latest advances in QDIPs and Superlattice infrared detectors at the Jet Propulsion Laboratory.
Large Format Multicolor QWIP Focal Plane Arrays
Mid-wave infrared (MWIR) and long-wave infrared (LWIR) multicolor focal plane array (FPA) cameras are essential for many DoD and NASA applications including Earth and planetary remote sensing. In this paper we summarize our recent development of large format multicolor QWIP FPA that cover MWIR and LWIR bands.
Mid-Wave and Long-Wave Infrared Dualband Megapixel QWIP Focal Plane Array
Mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) 1024x1024 pixel InGaAs/GaAs/AlGaAs based quantum well infrared photodetector (QWIP) focal planes and a 320x256 pixel dual-band pixel co-registered simultaneous QWIP focal plane array have been demonstrated as pathfinders. In this paper, we discuss the development of 1024x1024 MWIR/LWIR dual-band pixel co-registered simultaneous QWIP focal plane array.
Multi-Band and Broad-Band Infrared Detectors Based on III-V Materials for Spectral Imaging Instruments
Quantum well infrared photodetector technology has shown remarkable success by realizing large-format focal plane arrays in both broad-bands and in multi-bands. The spectral response of these detectors based on the III-V material system are tailorable within the mid and long wavelength IR bands (similar to 3-25 mu m) and possibly beyond. Multi-band and broad-band detector arrays have been developed by vertically integrating stacks of multi quantum wells tailored for response in different wavelengths bands. Each detector stack absorbs photons within the specified wavelength band while allowing the transmission other photons, thus efficiently permitting multiband detection. Flexibility in many design parameters of these detectors allows for tuning and tailoring the spectral shape according to application requirements, specifically for spectral imaging instruments.
Large format, multi-band QWIP FPAs for hyperspectral infrared imaging applications
Explore the source record for details and available documents.
Large format, 6-10 and 10-15 micron dual broad-band QWIP focal plane array
The Jet Propulsion Laboratory is developing a 512x640 format, dual broadband, Quantum Well Infrared Photodetector focal plane array for an imaing interferometer.
Large-format, dual broadband QWIP focal plane array for imaging interferometers
The Jet Propulsion Laboratory is developing a 512x640-format, dual broadband, Quantum Well Infrared Photodetector (QWIP) focal plane array (FPA for an imaging interferometer.
Theory of spin filtering in non-magnetic resonant tunneling diodes
Explore the source record for details and available documents.
Spin filtering in aysmmetric resonant interband tunneling diodes
Explore the source record for details and available documents.
Comment on Spin-filter device based on the Rashba effect using a nonmagnetic resonant tunneling diode
Explore the source record for details and available documents.