Measurements were made of the interdiffusion coefficient at CdTe/(Cd,Zn)Te interfaces by monitoring the evolution of the X-ray diffraction patterns of superlattices which were annealed at temperatures of between 360 and 420C, under a Cd over-pressure. A linear diffusion model was used to describe the experimental results. The interdiffusivity was described by:

D (cm2/s) = 1.00 x 102 exp[-2.5(eV)/kT]

The data agreed well with Cd self-diffusion coefficients which had been measured by using other techniques at temperatures of between 500 and 900C. This suggested that only one defect, probably the Cd vacancy, was involved in the diffusion process in the bulk material and at CdTe/(Cd,Zn)Te interfaces. At the growth temperatures (up to 280C) that were normally used for the molecular beam epitaxy of CdTe-based superlattices, the contribution of interdiffusion to the interface morphology could be neglected.

A.Tardot, N.Magnea: Journal of Crystal Growth, 1995, 148[3], 236-40