Dresden 2011 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 79: Photovoltaics: Mainly Silicon

HL 79.9: Talk

Thursday, March 17, 2011, 16:45–17:00, FOE Anorg

Estimation of the excess carrier concentration from the spectral photoluminescence yield — •Sebastian Knabe and Gottfried H. Bauer — Carl von Ossietzky Universität Oldenburg, Institut für Physik, Oldenburg, Deutschland

The photoluminescence emitted from excited semiconductors provides access to parameters like splitting of quasi-Fermi-levels, optical absorption, etc. and it is furthermore based on the recombination of excess carriers. In this study we show one option to estimate from photoluminescence measurements parameters, such as recombination lifetime, surface recombination velocity of the excess carriers for crystalline silicon. Therefore we simulate the spectral photoluminescence emitted from an excited silicon wafer with consideration of the excess carrier concentration mostly governed by surface recombination velocities, excess carrier lifetimes, diffusion lengths, as well as by optical absorption and reflection; the simulated PL fed to the detector also contains propagation of pl-photons across surfaces and according phase accumulation through layers formulated by a matrix transfer approach. The input parameters determining the excess carrier concentration are optimized with a generic algorithm to minimize the differences in numerically simulated spectral response and experimentally recorded photoluminescence using different functions to calculate the differences between simulation and measured spectrum. The application of this approach yields excess carrier depth profiles and according influences on spectral luminescence.