Serial sectioning was used to investigate the self-diffusion of 109Cd as a function of temperature (figures 6 and 7), component partial pressure and impurity content. It was found that the self-diffusion of undoped material at 650 to 900C was not appreciably affected by the partial pressure,

maximum pCd = Cd-saturation:     D (cm2/s) = 3.26 x 102 exp[-2.67(eV)/kT]

minimum pCd = Te-saturation:     D (cm2/s) = 1.58 x 101 exp[-2.44(eV)/kT]

but was enhanced by the presence of 5 x 1017/cm3 of an impurity-donor (Al) at 800 to 900C:

maximum pCd = Cd saturated:     D (cm2/s) = 1.37 x 10-7 exp[-0.67(eV)/kT]

It was concluded that the self-diffusion of Cd occurred via the motion of both ionised Cd vacancy acceptors and interstitial Cd donors. Ionised Frenkel disorder on the Cd sub-lattice represented the predominant high-temperature electrically active defect equilibria in CdTe.

Self-Diffusion of Cd and Te in CdTe. P.M.Borsenberger, D.A.Stevenson: Journal of the Physics and Chemistry of Solids, 1968, 29, 1277-86