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 largestI(D0,X)/Idefintensity ratio and the narrowest full width at half‐maximum of the main peak (D0,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‐temperature55Fe spectral response of the sample etched by the best treatment are also presented and discussed. ©1996 American Institute of Physics.