Photoluminescence for characterization of commercial semi-insulating GaAs

Abstract

Photoluminescence (PL) and selective pair luminescence (SPL) techniques were used to evaluate a large number of GaAs crystals. It was found that the results of these photoluminescence measurements, combined with data on carbon concentration obtained by local vibrational mode absorption spectroscopy, make possible an analysis of shallow impurities. Their relative concentrations were compared from seed to tail and from crystal to crystal and correlated to material resistivity. Impurities segregation in a crystal was analysed. Results of polariton line shape and intensity analysis were used in surface-related studies. Advantages of using both PL and SPL as a routine production analytical technique will be enhanced when the equipment for two-dimensional mapping of a whole GaAs wafer is completed.