Investigation of diffusion length and lifetime in lead chalcogenides by electron-beam-induced-current measurements at low temperatures

Abstract

The electron-beam-induced current (EBIC) mode of the scanning electron microscope has been used to study the temperature dependence of the minority-carrier diffusion length in PbTe and other IV-VI compounds (PbSnSe, PbSSe, PbCdS). The temperature dependence of the minority-carrier lifetime for PbTe has been deduced from diffusion-length measurements. Lifetime values of the order l×10−9–5×10−8 s have been found. Diffusion lengths and lifetimes as a function of carrier concentration have been studied. Discrepancies in the form of the EBIC signal have been found between PbTe diodes and ternary compound laser structures. A memory effect for PbSSe and PbCdS has been observed.