Extrinsic silicon detectors for 3–5 and 8–14 μm

Abstract

In support of system applications which operate in the 3–5 and 8–14 μm spectral ranges, high performance doped silicon detectors are desired to allow for the integration of detectors and silicon electronics on the same substrate. For the 8–14 μm range, detectors were prepared using aluminum, gallium, bismuth and magnesium as dopants which operate in the liquid neon temperature (27°K) range. For the 3–5μm range, detectors were prepared using indium, sulphur and thallium as dopants which operate in the liquid nitrogen temperature (78° K) range. The spectral and temperature characteristics of these detectors are presented. Background limited performance (∼30° FOV) is demonstrated for Si:Al. Si:Ga. and Si:Bi up to temperatures of about 30°K. Background limited performance (∼30° FOV) is demonstrated for Si:In and Si:S up to temperatures of approximately 60 and 75°K respectively. The data gives a good fit with theory based on background and temperature limitations. The performance of the Si:Mg detector is limited by a shallow unidentified energy level while that of the Si:TI detector is limited, at present, by low responsivity.