Readout of a Pb0.80Sn0.20Te detector array at 77K with a silicon CCD multiplexer

Abstract

Presented are some experimental results on the readout of a Pb0.80Sn0.20Te six-detector array at 77 K, coupled in the direct injection mode to a silicon CCD multiplexer. A 65 % typical injection efficiency is measured, in good agreement with the theoretical value, estimated from the dynamic impedance of the detector, and the input MOS transistor's transconductance. The detectors are reverse-biased between 15 and 25 mV, which is consistent with the injection efficiency and the ± 9 mV threshold voltage dispersion of the electrical inputs. The modulation amplitude shows a ± 15 % dispersion. An equivalent detectivity in excess of 2 × 1010W-1cm Hz1/2is measured at a 10 micron wavelength, limited by the noise current in the input MOS transistors.