Yagya D. Sharma

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We report on the multispectral properties of infrared photodetectors based on type II InAs/ Ga͑In͒Sb strain layer superlattices using an nBn heterostructure design. The optical and electrical properties of the midwave and long wave infrared ͑MWIR-LWIR͒ absorbing layers are characterized using spectral response and current-voltage measurements, respectively.(More)
—The quantum-confined Stark effect in intersublevel transitions present in quantum-dots-in-a-well (DWELL) detectors gives rise to a midIR spectral response that is dependent upon the detector's operational bias. The spectral responses resulting from different biases exhibit spectral shifts, albeit with significant spectral overlap. A postprocessing(More)
The authors report the design, growth, fabrication, and characterization of a low-strain quantum dots-in-a-well ͑DWELL͒ infrared photodetector. This novel DWELL design minimizes the inclusion of the lattice-mismatched indium-containing compounds while maximizing the absorption cross section by enabling larger active region volume. The improved structure(More)
In this paper, we report a successful realization and integration of a gold two-dimensional hole array (2DHA) structure with semiconductor InAs quantum dot (QD). We show experimentally that a properly designed 2DHA-QD photodetector can facilitate a strong plasmonic-QD interaction, leading to a 130% absolute enhancement of infrared photoresponse at the(More)
—The use of resonant tunneling (RT) barriers in the design of quantum dots-in-a-well (DWELL) infrared photodetectors is reported. The design of RT barriers for a variety of goals has been discussed. For simple DWELL designs, we demonstrate 2–3 orders-of-magnitude reduction in the dark current, with significant increase in the specific detectivity () of the(More)
A midwave infrared camera ͑␭ c = 4.2 ␮m͒ with a 320ϫ 256 focal plane array ͑FPA͒ based on type-II InAs/ GaSb strain layer superlattice ͑SLs͒ has been demonstrated. The detectors consist of an nBn heterostructure, wherein the SL absorber and contact layers are separated by a Al 0.2 Ga 0.8 Sb barrier layer, which is designed to have a minimum valence band(More)
— Mid-wave and long-wave infrared (IR) quantum-dots-in-a-well (DWELL) focal plane arrays (FPAs) are promising technology for multispectral (MS) imaging and sensing. The DWELL structure design provides the detector with a unique property that allows the spectral response of the detector to be continuously, albeit coarsely, tuned with the applied bias. In(More)
We report on a type-II InAs/ GaSb strain layer superlattice photodetector using a nBn design with cutoff wavelength of ϳ4.8 ␮m at 250 K. The surface component of dark current was eliminated. Using a shallow isolation etch, low temperature dark current was reduced by two orders of magnitude compared with conventional photodiode processing. Dark current(More)