Minority carrier diffusion length measurements in CdTe by a photocurrent technique

Abstract

A simple technique for measuring the minority carrier diffusion length in semiconductors is demonstrated. The technique does not require the knowledge of any parameter of the investigated material. It consists, basically, in measuring the photocurrent of a semiconductor-electrolyte Schottky barrier, as a function of applied reverse bias. Weakly absorbed light is used, so that the light penetration depth is much larger than the Schottky barrier width. The diffusion length of n-type CdTe doped at a concentration of 8×1014/cm3 is found to be 1.75 μm.