A focal plane array detector sensitive from 2.0-2.5 μm and consisting of 32, 1.0 mm x 50 μm pixels, all functional, is demonstrated. Mean room-temperature R0A is found to be 1.0 Ωcm2, limited by sidewall leakage. The focal plane array is fabricated from an MBE-grown homojunction p-i-n GaInAsSb grown on an n-type GaSb substrate. Back-illumination geometry is compared to front-illumination geometry and is found to be favorable, particularly the improved responsivity (1.3 A/W at 2.35 μm corresponding to 68% quantum efficiency) due to reflection of light off the metal contact. Further, back-illumination is the most convenient geometry for mounting the array onto a compact blood glucose sensor because both contacts can be mounted on one side, while detector illumination occurs on the other.
John P. Prineas, Madhusudhana Reddy, Jonathon T. Olesberg
Journal name not available for this finding