Low-temperature photoluminescence of detector grade Cd1-xZnxTe crystal treated by different chemical etchants

Low-temperature photoluminescence (PL) spectra of detector grade Cd1-xZnxTe (x=0.1) have been measured to obtain information about shallow level defect concentration introduced during mechanical polishing and chemical etching processes. We present here a comparative PL study of Cd0.9Zn0.1Te crystals treated by different chemical solutions used for nuclear detector surface treatment. The results show that the 5% Br-MeOH+2%Br-20% lactic acid in ethylene glycol treatment combines the advantages of bromine and lactic acid for chemical etching and results in the best surface condition, as evidenced by the largest I(D-0,X)/I-def intensity ratio and the narrowest full width at half-maximum of the main peak (D-0,X). Changes in the surface morphology were also analyzed by atomic force microscopy and correlated with the PL results. Current-voltage (I-V) curves and the room-temperature Fe-55 spectral response of the sample etched by the best treatment are also presented and discussed. (C) 1996 American Institute of Physics.