Surface cracking in zinc diffused CdTe

CdTe slices have been diffused in sealed silica capsules under conditions of saturated vapor pressure due to zinc in the temperature range 390–950°C. All slices annealed with zinc at temperatures above 450°C displayed extensive surface cracking both by slip along specific crystallographic planes and by brittle fracture, whereas below this temperature no such effects were detected. In addition, some slices diffused at 800°C with small quantities of zinc, which was insufficient to maintain saturated vapor pressure throughout the diffusion experiment, did not show any cracks. The interpretation of this behavior can be divided into three temperature ranges and can be explained in terms of the critical resolved shear stress and the misfit ratio. This is discussed extensively in this paper.