Trapping-related recombination of charge carriers in silicon

Abstract

In this paper we show experimental results that indicate that trapping-related increase of the apparent carrier lifetime can be directly accompanied by a decreased recombination lifetime. This effect cannot be described with the traditionally used trapping model of Hornbeck and Haynes [1,2,3] (H&H). In order to obtain a physically consistent theoretical description of the observed correlation between trapping and recombination we use the Shockley, Read [4] and Hall [5] (SRH) formalism. We assume trap states with non-zero capture cross sections for majority carriers, which may nevertheless be several orders of magnitude smaller than the minority carrier capture cross sections. In this way we define a Recombination-Active Trap state (RAT) that allows a simultaneous description of trapping effects and a reduction of the recombination lifetime in low level injection.