Investigation of electrical contacts for Cd/sub 1-x/Zn/sub x/Te nuclear radiation detector

A comparative study of four different metal deposition methods on detector grade Cd/sub 1-x/Zn/sub x/Te crystal has been done using current-voltage (I-V) characterization and /sup 133/Ba gamma spectroscopy. An electroless Au contact and thermal evaporated Au contact have been found to yield a smaller leakage current and a more linear/symmetric I-V curve than that of sputtered Pt and Au contact. An optimum detector performance can be achieved by combining the thermal evaporated Au deposition method with a chemical surface treatment consisting of 5% Br MeOH followed by 2% Br-20% lactic acid in ethylene glycol. Low temperature photoluminescence spectra of Cd/sub 1-x/Zn/sub x/Te samples corresponding to these different metallization schemes are also presented and discussed.