Discrimination of the Substrate-Induced Artifact from the Photoluminescence Peak of Heavily Doped GaAs

Abstract

We have studied the temperature-dependent behavior of the photoluminescence (PL) peak known to be due to the donor-acceptor (DA) pail recombination in heavily Si-doped GaAs. In some cases, the 1.49-eV PL peak is observed to appear up to much higher temperature than a normal DA peak is. The temperature dependence of this peak energy is very similar to that of the band-gap energy. From this fact, it is pointed out that this abnormal PL peak must be an artifact due to the remaining spectral region of the PL spectrum after the PL Light is absorbed in the epilayers and the substrate, between which it travels back and forth.