The diffusion of Zn into bulk-grown material was studied at 800C as a function of the annealing time and the mass of the diffusion source. The diffusion was carried out in evacuated silica ampoules, and the diffusion profiles were measured by using a radiotracer sectioning technique; although some measurements were obtained by using scanning electron microscopy with an EDAX attachment. When the mass of Zn which was placed in the ampoule exceeded 2mg, Zn0.8Cd0.2Te formed on the surface of the slice early in the diffusion process and the diffusion profiles consisted of 2 components. Two values of the diffusivity were obtained, a slow value (2 x 10-11cm2/s) and a fast value (2 x 10-10cm2/s), for annealing times which exceeded 6h and when a mass of Zn of 8mg was placed in the ampoule. This was compared with the result which was obtained when the mass of Zn was less than 2mg. Here, no surface layer of the ternary compound formed, and diffusion profiles which consisted of a single component were obtained. It was proposed that 2 diffusion mechanisms operated: one was due to Zn atoms which diffused from the vapor and into the ZnCdTe layer, and the other involved interdiffusion between the ternary compound at the surface of the slice and CdTe in the bulk.

E.D.Jones, J.C.Clark, J.B.Mullin, A.W.Brinkman: Journal of Crystal Growth, 1994, 138[1-4], 274-8