Influence of luminescence self-absorption on photoluminescence decay in GaAs

In direct-gap semiconductors, self-absorption processes are known to increase minority carrier lifetimes. In this paper, an original method is developed to solve the dynamic continuity equation with the inclusion of self-absorption phenomena. Also named photo recycling, this process is treated in a model which takes into account the experimental conditions, together with geometrical and optical characteristics of the sample. This method is used to analyze photoluminescence decay experiments on angle-lapped GaAs/Ga0.15Al0.85As double heterostructures. The inclusion of the reabsorption effects is shown to improve the global fit of calculated luminescence with experimental data. This leads to a more accurate determination of key electronic parameters such as diffusion coefficient, surface recombination velocities, and nonradiative lifetime of minority carriers.