Electrochemical texturization of ZnTe surfaces

We report the results of electrochemical etching on ZnTe crystals using the acidic etchant HNO3:HCl:H2O. Under optimized conditions we are able to etch several micrometer deep patterns into 〈111〉 and 〈110〉 surfaces. A comparison between etched and polished crystals shows that a surface enlargement of approximately 50 times can be obtained. The etched surfaces have strongly reduced optical reflectance, high photoluminescence efficiency, and excellent photosensitivity. Needlelike structures can be prepared, which exhibit a blueshift of the excitonic transition energies, indicating that parts of the etch pattern are in the quantum confinement regime.