VAPOUR-PRESSURE INVESTIGATIONS OF IMPURITY DIFFUSION AND SOLUBILITY IN A2-B6 COMPOUNDS DEMONSTRATED FOR SYSTEM CDS - AU - S2

It is shown that for investigations of disorder problems in AII–BVI compounds it is relevant to measure the diffusion coefficient D and the solubility S as functions of the vapour pressure p of the components. Using the tracer technique this method is exemplified in detail for a cation impurity diffusion process in the system CdS:Au:S2. The measured concentration profiles C(x) are not of Fick's type. After eliminating surface and dislocation diffusion (Fisher analysis), D(T, p, C) and also simultaneously S(T, p) can be obtained. The results are explained in a disorder model with controlled intrinsic disorder. It is found that gold diffuses in CdS via singly‐charged cadmium vacancies and acts as a singly‐charged acceptor. Copyright © 1968 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim