Morphological effects and the diffusion of iodine in CdTe

The morphology of undiffused and iodine-diffused CdTe slices and its effect on iodine concentration profiles is discussed. Such CdTe slices were analysed using defect etching, scanning electron microscopy (SEM), infrared microscopy and secondary ion mass spectrometry (SIMS). The results suggest that during diffusion a layer of an iodine compound forms in the surface region of the CdTe while, over a limited range further into the material, clusters of either this or a similar compound form at defect sites causing a high degree of crystal distortion.