Multi-Species Diffusion in CdTe

We studied theoretically chemical self-diffusion and the diffusion of extrinsic atoms in CdTe. We compiled a general model describing the multi-species diffusion of arbitrary amounts of elements in a form optimized for numerical calculations and applied it to a model system of CdTe doped with slow- or fast-diffusing elements. The diffusion of slowly diffusing atoms was analyzed and compared with experimental findings. We uncovered possible drawbacks in the experimental data that might affect the ensuing analysis by researchers, so generating incorrect conclusions. We suggest a method of purifying CdTe from fast-diffusing impurities based on a proper annealing/etching process.