SUPERLATTICE MATERIALS FOR THE NEXT GENERATION OF LONG WAVELENGTH INFRARED DETECTORS

New infrared (IR) detector materials with high sensitivity, multi-spectral capability, improved uniformity and lower manufacturing costs are required for numerous space-based infrared imaging applications. To meet these stringent requirements, new materials must be designed and grown using semiconductor heterostructures, such as quantum wells and superlattices, to tailor new optical and electrical properties unavailable in the current generation of materials. One of the most promising materials is a strained layer supperlattice (SLS) composed of thin InAs and GaInSb layers. While this material shows theoretical and early experimental promise, there are still several materials growth and processing issues to be addressed before this material can be transitioned to the next generation of infrared detector arrays. Our research is focused on addressing the basic materials design, growth, optical properties, and electronic transport issue of these superlattices.

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Next-generation long-wavelength infrared detector arrays: competing technologies and modeling challenges

Integrated Optics Volume 2: Characterization, devices and applications ◽

10.1049/pbcs077g_ch9 ◽

2020 ◽

pp. 265-294

Keyword(s):

Infrared Detector ◽

Next Generation ◽

Detector Arrays ◽

Long Wavelength ◽

Long Wavelength Infrared ◽

Competing Technologies

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A Long-Wavelength Infrared Photoluminescence Spectrometer for the Characterization of Semiconductor Materials

MRS Proceedings ◽

10.1557/proc-299-35 ◽

1994 ◽

Vol 299 ◽

Author(s):

R. P. Wright ◽

S. E. Kohn ◽

N. M. Haegel

Keyword(s):

Infrared Detector ◽

Optical Emission ◽

High Sensitivity ◽

Radiation Emission ◽

Long Wavelength ◽

Ion Laser ◽

Detector Materials ◽

Long Wavelength Infrared ◽

Argon Ion

AbstractA new photoluminescence spectrometer has been developed for the characterization of optical emission in the 2.5 to 14.1 micron wavelength range. This instrument provides high sensitivity for the detection of interband and defect luminescence in a variety of infrared detector materials. The spectrometer utilizes a solid state photomultiplier detector and a circular variable filter, which serves as the resolving element. The entire spectrometer is cooled to 5K in order to decrease thermal radiation emission. Band-edge luminescence at 10.1 microns from HgCdTe samples has been readily detected with argon-ion laser excitation powers less than 70 mW/cm2. Representative spectra from HgCdTe and other infrared detector materials are presented.

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Quantum Well and Quantum Dot Based Detector Arrays for Infrared Imaging

MRS Proceedings ◽

10.1557/proc-1076-k03-02 ◽

2008 ◽

Vol 1076 ◽

Cited By ~ 2

Author(s):

Sarath Gunapala ◽

Sumith Bandara ◽

Cory Hill ◽

David Ting ◽

John Liu ◽

...

Keyword(s):

Quantum Well ◽

Infrared Imaging ◽

Incident Light ◽

Focal Plane Arrays ◽

Infrared Photodetector ◽

Detector Arrays ◽

Long Wavelength ◽

Quantum Well Infrared Photodetector ◽

Long Wavelength Infrared ◽

Reflection Grating

ABSTRACTA mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) 320x256 pixel quantum well infrared photodetector (QWIP) dualband focal plane arrays (FPAs) have been demonstrated with excellent imagery. Currently, we are developing a 1024x1024 pixel simultaneous pixel co-registered dualband QWIP FPA. In addition, epitaxially grown self-assembled InAs/InGaAs/GaAs quantum dots (QDs) are exploited for the development of large-format FPAs. The Dot-in-a-Well (DWELL) structures were experimentally shown to absorb both 45° and normal incident light, therefore a reflection grating structure was used to enhance the quantum efficiency. The devices exhibit peak responsivity out to 8.1 microns, with peak detectivity reaching ∼ 1 × 1010 Jones at 77 K. The devices were fabricated into the first LWIR 640x512 pixel QDIP FPA, which has produced excellent infrared imagery with NETD of 40 mK at 60K operating temperature.

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Intersubband Transitions in InxGa1-xAs/AlGaAs Multiple Quantum Wells for Long Wavelength Infrared Detection

MRS Proceedings ◽

10.1557/proc-744-m9.7 ◽

2002 ◽

Vol 744 ◽

Author(s):

Clayton L. Workman ◽

Zhiming Wang ◽

Wenquan Ma ◽

Christi E. George ◽

R. Panneer Selvam ◽

...

Keyword(s):

Quantum Wells ◽

Infrared Detector ◽

Indium Content ◽

Multiple Quantum Wells ◽

Band Offset ◽

Multiple Quantum ◽

Material System ◽

Intersubband Transitions ◽

Long Wavelength ◽

Long Wavelength Infrared

ABSTRACTWe report on intersubband transitions in InxGa1-xAs/AlGaAs multiple quantum wells (MQWs) grown by molecular beam epitaxy. The conduction band offset for this material system is larger than that of the well known GaAs/AlGaAs system, thus making it possible to design, grow, and fabricate quantum well infrared photodetectors operational beyond the 14 μm spectral region with minimized dark current. We have grown InxGa1-xAs/AlGaAs MQWs with indium compositions ranging from x = 0.08 to 0.20 verified by in situ RHEED oscillations, band offset measurements, and high-resolution X-ray diffraction. Band-to-band transitions were verified by photoluminescence measurements, and intersubband transitions were measured using Fourier transform infrared (FTIR) spectroscopy. Due to the high strain and introduction of dislocations associated with the high indium content, wells with indium compositions above ∼ 0.12 did not result in intersubband transitions at silicon doping levels of 2×1018 cm-3. A thick linear graded InxGa1-xAs buffer was grown below the MQW structures to reduce the strain and resulting dislocations. Intersubband transitions were measured in InxGa1-xAs wells with indium compositions of x = 0.20 and greater when grown on top of the linear graded buffer. In addition to these results, FTIR measurements on InGaAs/AlGaAs MQW multi-color, long-wavelength infrared detector structures are reported.

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