Study of gamma-ray detector performance of Cd1-xZnxTe crystal treated by different etchants

Radiation detectors have been fabricated from Cd1-xZnxTe crystals and their performance has been studied with respect their Cd1-xZnxTe surface preparation. Energy resolution, leakage current, resistivity, ohmicity as well as surface roughness of the detectors were measured and compared for various chemical treatments. Etching in lactic acid has been found to lead to better ohmic contract, a rougher surface and higher leakage current. Bromine is effective in removing the damaged layer and when added to 20 percent lactic acid in ethylene glycol leads to a lower leakage current and consequently a better energy resolution. The best detector performance was obtained with a two step treatment consisting of a standard etchant (5 percent Br in methanol) followed by 2 percent Br in'20 percent lactic acid in ethylene glycol'. The results clearly demonstrate the important of surface chemical treatments in the fabrication of Cd1-xZnxTe radiation detectors.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.