Studies on the diffusion of the halogens into CdTe

A comparison of the diffusion of the halogens into CdTe is given. Diffusion anneals were carried out at selected temperatures in the range between 20 and in evacuated silica ampoules using a diffusion source of , or under saturated vapour pressure conditions. The concentration profiles were measured using either a radiotracer sectioning (RTS) technique or secondary-ion mass spectrometry (SIMS). In most cases the profiles were found to be composed of four parts to which a computer package consisting of the sum of four complementary error functions (erfc) gave satisfactory fits to the data. This fitting method was purely empirical but it proved to be satisfactory to describe the diffusion profiles as well as to show how the diffusivities behaved with various parameters. Proposals explaining how this type of diffusion may occur are given.