Effects of Hg Annealing on Photoluminescence Spectra of CdTe Crystals and MOCVD-Grown CdTe/GaAs Films

Abstract
Annealing effects on CdTe crystals and CdTe/GaAs films in Hg have been investigated through the spectral changes of PL (photoluminescence) at 4.2 K. Before annealing, the PL spectrum of CdTe crystals or films is dominated by the excitonic-emission lines, the edge-emission band and two broad bands. After annealing, a marked decrease in intensity of the broad and edge-emission bands in the bulk crystals is observed, while an increase in intensity of the broad bands in the MOCVD-grown CdTe is significant. We will point out from the PL investigations that the Hg annealing plays an important role in the improvement of both the surface and bulk properties.