The electrodiffusion of Cu into nominally undoped high-resistivity crystals was investigated at 250 to 400C. A strong diffusional anisotropy was observed; with Cu diffusion perpendicular to the c-axis being more than an order of magnitude faster than that parallel to the c-axis. This effect was not due to a greater dislocation density perpendicular to the c-axis, than parallel to the c-axis, as previously suggested. Electrically active dislocations which lay in the basal plane were suggested to be channels of rapid diffusion; due to their concentrated decoration with intrinsic defects and residual impurities.

On the Nature of Diffusion Anisotropy in CdS Crystals. L.V.Borkovskaya, B.R.Dzhumaev, L.Y.Khomenkova, N.E.Korsunskaya, I.V.Markevich, M.K.Sheinkman: Semiconductor Physics, Quantum Electronics & Optoelectronics, 2000, 3[3], 282-6