HgCdTe/CdTe heterostructure diodes and mosaics

This paper discusses the results of a study of the properties of HgCdTe/CdTe heterostructure diodes and mosaics. P-type HgCdTe epi-layers on the order of 20 microns were grown on CdTe substrates by a liquid-phase epitaxial (LPE) technique. These layers normally had a carrier concentration of 5 times 10 to the 16th/cu cm and a mobility of 400 sq cm/V.s at 77 K. The n(+)-p junction was formed by boron ion implantation, and standard photolithographic techniques were used for the device fabrication. The diodes with no antireflection coating had a typical quantum efficiency of 40 percent. The 1/f noise knee was on the order of 10 Hz at zero bias. Surface leakage seemed to be the dominant component for diodes at temperatures less than 77 K. From mosiac studies, it was found that the spectral spread was less than + or - 0.3 microns for an area as large as 12 by 20 mm. The study indicates that LPE offers a viable technique for producing high-quality HgCdTe epi-layers on CdTe.