Sandia Labs FY22 Laboratory Directed Research & Development Annual Report

DEVELOPING LARGE, HIGH-UNIFORMITY FOCAL PLANE ARRAYS FOR REMOTE SENSING THROUGH LOW-DARK-CURRENT EXTENDED-SHORT-WAVE DETECTORS.

High-performance focal plane array detectors with long-wavelength cutoffs in the spectral range from 1.7 to 3.0 µm traditionally use mercury cadmium telluride (HgCdTe) as the photon-absorbing material. Detectors made from group-III and group-V elements offer potentially similar performance with reduced cost, improved manufacturability, and superior scaling to large arrays, but development of the required materials has lagged that of III-V detectors in the mid- and long wavelength infrared. This Sandia LDRD team examined relatively unexplored III-V alloys for this application and obtained high-quality, single-phase quaternary materials, yielding

Relative external spectral quantum efficiency for devices.

detectors with cutoff wavelengths from 2.55 to 3.2 µm. Large-area detectors had high quantum efficiencies with dark currents like state-of-the art HgCdTe detectors for cutoff wavelengths longer than 2.9 µm. A new set of materials was identified through this effort that may be exploited to produce large, high-uniformity focal plane arrays for remote sensing. One

The team designed a focal plane array detector with cutoff wavelengths from 2.55 to 3.2 µm.

publication resulted to date from this project, and two presentations were provided at events focused on military sensing technologies. (PI: John Klem)

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LABORATORY DIRECTED RESEARCH & DEVELOPMENT