Cd<i>x</i>Hg1−<i>x</i>Te INFRARED PHOTOVOLTAIC DETECTORS

Abstract

Using departure from stoichiometry for doping, p-n junctions were prepared from CdxHg1−xTe alloys with 0.15 &amp;lt; x ≤ 0.28, and their current-voltage characteristics were measured at 77°K. The spectral study of these photovoltaic detectors operating at 77°K showed responses from 3 μ up to 17.5 μ. Detectivity measurements at the wavelengths of maximum response of these detectors yielded values at 77°K between 1 and 5 × 109 cm-W−1-Hz1/2 in the range 3 to 14 μ. The speed of these detectors was measured to be &amp;lt;50 nsec, which was also confirmed by the observation of mode beats on the continuous output of a low-power CO2 laser at several frequencies up to 25 MHz.