Surface texturisation of ZnTe crystals and thin films

Electrochemical etching has been employed for the texturisation of crystall ine ZnTe surfaces. Under optimised conditions micrometre-deep etchings patt erns can be obtained. The etched surfaces show a factor-3 decrease in the r eflectivity at normal incidence, and a 30% increase in the electrical photo sensitivity. When the etching is sufficiently deep, needle-like structures with an aspect ratio larger than 10 appear. These deeply etched surfaces ex hibit a blue shift in the excitonic photoluminescence, indicative of electr on confinement effects. (C) 2000 Elsevier Science S.A. All rights reserved.