Identification of EL2 as the lifetime-limiting defect using temperature-dependent photoluminescence decay with linearization method to decouple effects of diffusion and surface recombination

Surface recombination and diffusion screen measurements of the bulk lifetime in photoluminescence decay experiments. In this work, we introduce a linearization method, derived from our analytical solution to the three-dimensional diffusion problem in cylindrical coordinates, demonstrating that it allows an accurate measurement of the bulk lifetime in GaAs from 77K to 700K. This robust linearization method enables temperature-dependent bulk lifetime measurements on thick, unpassivated, strongly absorbing materials, which allow for characterization and identification of the defects that limit lifetime and photovoltaic efficiency. We apply this linearization technique to perform a temperature-dependent lifetime analysis, and find evidence that the EL2 defect is the dominant nonradiative recombination center.