Achievement

Time-resolved photoluminescence is an established technique for characterizing carrier lifetimes in semiconductors, but the dependence of lifetime on excitation fluence has been only qualitatively investigated. We develop a quantitative approach for fitting fluence-dependent PL decay data to a Shockely-Read-Hall model of carrier recombination in order to extract the trap state density. We demonstrate this approach by investigating growth rate-dependent trap densities in gallium arsenide - indium gallium phosphide double heterostructures. The techniques developed here can be applied for rapid, non-destructive quantification of trap state densities in a variety of materials. Accepted by:

C.R. Haughn, K.J. Schmieder, J.M.O. Zide, A. Barnett, C. Ebert, R. Opila, and M. F. Doty. Quantification of trap state densities in GaAs heterostructures grown at varying rates using intensity-dependent time resolved photoluminescence. Appl. Phys. Lett. 102, 182108 (2013).