<title>Characterization Of Deep Impurities In GaAs By Photoluminescence</title>

Abstract

We have measured systematically low-temperature photoluminescence spectra associated with deep acceptors due to 3d transition metals in GaAs bulk crystals in order to get some basic knowledge necessary for the characterization of these deep acceptors and related impurities or defects in GaAs. A series of the 3d transition metals, Cr, Mn, Fe, Ni and Cu, in GaAs have been studied, the luminescence spectra showing some characteristic emission lines for each transition metal in the near-infrared region. These results provide a spectroscopic characterization method for the identification of these impurities in GaAs. Analysis of the luminescence data indicates the formation of various complexes including a transition metal with another defect or shallow impurity. The in-depth profiles of these deep center luminescence intensities have been measured for the cases of Cr and Ni, the results indicating the usefulness of the photoluminescence technique for the characterization of the in-depth profiles of shallow impurities and defects such as an arsenic vacancy. In particular, the in-depth profile of the Cr-related luminescence line in annealed GaAs:Cr has been studied to investigate the distribution of such defects in GaAs crystals.