Super high voltage Schottky diode with low leakage current for x- and γ-ray detector application

A significant improvement in x-/γ-ray detector performance has been achieved by forming both rectifying and near-Ohmic contacts by the deposition of Ni on opposite surfaces of semi-insulating CdTe crystals pretreated by special chemical etching and Ar-ion bombardment with different parameters. The reduced injection of the minority carriers from the near-Ohmic contact in the neutral part of the diode provides low leakage current even at high bias (<50 nA/cm2 at 2000 V and 293 K). The electrical properties of the detectors are well described quantitatively by the generation-recombination Sah–Noyce–Shockley theory excepting the high reverse voltage range where some injection of minority carriers takes place.