Au-doped HgCdTe for infrared detectors and focal plane arrays

Recently, it was reported that p-type, Au-doped HgCdTe epilayers have a carrier lifetime two to three times higher than the Hg-vacancy doped epilayers with the same condition type. Analysis of the temperature dependent Hall measurement results indicates the existence of vacancy complexes in the vacancy doped HgCdTe epilayers but not in the Au-doped epilayers. Therefore, it is very likely that the defect complexes are generation-recombination centers, which reduce the carrier lifetime. Shortwave, midwave, and longwave HgCdTe diodes arrays have been produced in the Au-doped HgCdTe epilayers by the ion implantation technique. The n- type conversion by implantation is explained by the formation of tellurium antisites. Excellent array performances have been observed. Comparing these arrays to the heterojunction HgCdTe arrays, the arrays formed by ion implantation perform similar to or even better than the heterojunction array at liquid nitrogen temperature, but are inferior to the heterojunction arrays at a temperature over 150K.