INVESTIGATION OF ELECTRICAL CONTACTS FOR CD1-XZNXTE NUCLEAR RADIATIONDETECTORS

A comparative study of four different metal deposition methods on dete ctor grade Cd1-xZnxTe crystal has been done using current-voltage (I-V ) characterization and Ba-133 gamma spectroscopy. Electroless Au conta ct and thermal evaporated Au contact have been found to yield a smalle r leakage current and a more linear/symmetric I-V curve than that of s puttered Pt and Au contact. An optimum detector performance can be ach ieved by combining the thermal evaporated Au deposition method with a chemical surface treatment consisting of 5%Br-MeOH followed by 2% Br-2 0% lactic acid in ethylene glycol. Low temperature photoluminescence s pectra of Cd1-xZnxTe samples corresponding to these different metalliz ation schemes are also presented and discussed.