Unified model for the luminescence and transport data in self-supporting porous silicon

Abstract

The results of a combined study of the temperature variation of photoluminescence (PL) and dc conductivity from high optical-quality free-standing porous silicon films are presented. PL spectra of the samples have been studied in the range 10–300 K. Dc conductivity (σ) on these samples have been studied from 90 to 300 K in the voltage range 0.25–1.5 V. We attempt to understand the luminescence and transport data in terms of a recently proposed unified model. The conductivity (σ) exhibits a Berthlot-type temperature variation [≅exp(T/TB)]. The luminescence data can be explained in terms of a competition between an activated radiative process [≅ exp−(Tr/T)] and a Berthlot-type hopping process. The Berthlot temperature “TB” obtained independently from the transport and luminescence data are in approximate agreement.