The Lifetime of Charge Carriers in PbS

Abstract

The lifetime of current carriers is one of the important characteristics of a semiconductor. Its measurement is complicated by the presence of several recombination or trapping mechanisms in the bulk and the surface of a crystal. In the case of germanium, techniques have been developed for studying some of the above mechanisms. In this paper two experimental techniques will be described which were developed to help clarify some of the problems related to carrier lifetimes in PbS crystals. The first provides a simple way of obtaining a clean surface on a PbS single crystal suitable for studying the effect of adsorbed ambients on the lifetime or studies of other surface phenomenon. The second is a procedure for studying the defects in PbS crystals and their effect on the lifetime.