DONOR IDENTIFICATION IN BULK GAAS BY FOURIER-TRANSFORM PHOTOLUMINESCENCE

The identification of substitutional shallow donors in GaAs by optical techniques has been problematic because of the extremely small chemical shifts of these effective-masslike impurities. Photoluminescence has been successfully applied in identifying donors in high-purity epitaxial material through the painstaking use of high-resolution spectroscopy, high-magnetic fields, and resonant excitation. Relatively little work has been done in bulk GaAs, where the broadened transitions hinder the resolution of different species. Recently we demonstrated that the high resolution and high-signal throughput obtained with Fourier transform photoluminescence (FTPL) gives superior results for epitaxial material. In this report we show that the advantages of FTPL can also be applied to reliable donor identification in bulk GaAs.