Correlation of photoluminescence measurements with the composition and electronic properties of chemically etched CdTe surfaces

Abstract

We have performed photoluminescence (PL) measurements on chemically etched single-crystal p-CdTe. In addition, x-ray photoemission measurements have been used as a guide to surface stoichiometry for each chemical treatment. The relative intensities of the 0.875±0.005 eV and 1.125±0.005 eV PL bands are seen to be linked to the preferential depletion of either Cd or Te from the CdTe surface. Furthermore, the energies of these deep level transitions measured at T=4 K show remarkable agreement with the two values of Schottky barrier, Φb=0.72±0.02 eV and Φb=0.93±0.02 eV, normally obtained at room temperature for Au and Sb contacts to n-CdTe.