Characteristics of n-type InSb

The paper reports photoconductive data on n-type InSb detectors made from a high quality state-of-the-art ingot. From Hall measurements, impurity carrier concentration was found to be 5.5 x 10 to the 13th per cu cm at 77 K and recombination center density was estimated to be 8 x 10 to the 13th per cu cm. Noise, responsivity, and photoconductive lifetime as a function of temperature and background photon flux density (2 x 10 to the 14th to 8 x 10 to the 15th photons/sq cm/sec) were measured. It is shown that at temperatures up to 200 K recombination through Shockley-Read centers limits the photoconductive lifetime; above 250 K an Auger type process determines the photoconductive lifetimes.