ABSTRACT
We investigated the origin of the short-period oscillation(SPO) in photoreflectance(PR) spectra of selectively doped GaAs samples. In the PR spectra of the samples the SPO are separated into two distinct signals. The intensity of the lower-energy signal decreases rapidly as temperature is lowered. Therefore, we conclude that the short-period oscillation is due to the hole-ionized acceptor (h-A-) pair modulation and the free exciton modulation in the cap layer.
