Contactless determination of current–voltage characteristics and minority-carrier lifetimes in semiconductors from quasi-steady-state photoconductance data

A simple method for implementing the steady-state photoconductance technique for determining the minority-carrier lifetime of semiconductor materials is presented. Using a contactless instrument, the photoconductance is measured in a quasi-steady-state mode during a long, slow varying light pulse. This permits the use of simple electronics and light sources. Despite its simplicity, the technique is capable of determining very low minority carrier lifetimes and is applicable to a wide range of semiconductor materials. In addition, by analyzing this quasi-steady-state photoconductance as a function of incident light intensity, implicit current–voltage characteristic curves can be obtained for noncontacted silicon wafers and solar cell precursors in an expedient manner.