Recently published data on Hg diffusion in Hg0.8Cd0.2Te and CdTe were compared. It was noted that, as usual, 2 component profiles were observed in most cases; with the profiles yielding differing diffusivities. It was found that the coefficients for Hg diffusion in CdTe were much lower than the corresponding values for Hg0.8Cd0.2Te. In the latter, diffusion occurred via volume diffusion followed by short-circuit diffusion. In CdTe, diffusion was rate-limiting volume diffusion which involved a slow stream and a fast stream. On the basis of pressure-dependence data, it was proposed that the slow component involved an interstitial mechanism at low Hg partial pressures, and a vacancy mechanism at high Hg partial pressures. In the case of Hg0.8Cd0.2Te, the reverse occurred with regard to the fast-diffusion component. In CdTe, the slow component increased systematically with etch-pit density whereas, in Hg0.8Cd0.2Te, the diffusivity was independent of the quality of the material.

M.U.Ahmed, E.D.Jones, J.B.Mullin, N.M.Stewart: Journal of Electronic Materials, 1996, 25[8], 1260-5