LOW-TEMPERATURE PHOTOLUMINESCENCE OF DETECTOR-GRADE CD1-XZNXTE CRYSTAL TREATED BY DIFFERENT CHEMICAL ETCHANTS

Low-temperature photoluminescence (PL) spectra of detector grade Cd1-x ZnxTe (x=0.1) have been measured to obtain information about shallow l evel defect concentration introduced during mechanical polishing and c hemical etching processes. We present here a comparative PL study of C d0.9Zn0.1Te crystals treated by different chemical solutions used for nuclear detector surface treatment. The results show that the 5% Br-Me OH+2%Br-20% lactic acid in ethylene glycol treatment combines the adva ntages 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 m ain peak (D-0,X). Changes in the surface morphology were also analyzed by atomic force microscopy and correlated with the PL results. Curren t-voltage (I-V) curves and the room-temperature Fe-55 spectral respons e of the sample etched by the best treatment are also presented and di scussed. (C) 1996 American Institute of Physics.