Effect of surface preparation on the 77 K photoluminescence of CdTe

Abstract

Photoluminescence spectra were obtained at 77 K for three undoped CdTe single crystal specimens whose surfaces were prepared by mechanical, conventional chemimechanical, and modified hydroplane polishing techniques, respectively. The hydroplane polished sample was found to be a much brighter source of photoluminescence than either of the other two specimens. In addition, hydroplane polishing produced a photoluminescence spectrum in which nearly all of the emission occurred in a band centered at 1.58 eV rather than in the well-known defect band at 1.42 eV. We interpret these results as providing evidence that hydroplane polishing of CdTe produces a surface having a low density of defects.