The formation of defects during Zn diffusion into undoped or semi-insulating Fe-doped single crystals at 700C was observed by means of transmission electron microscopy under various diffusion conditions. Agglomerates of predominantly perfect interstitial-type dislocation loops, dislocations, and small In precipitates within voids were observed in the Zn-diffused region. Also, large planar arrays of precipitates were formed by climbing dislocations. From these observations, it was deduced that the incorporation of Zn at In sub-lattice sites created a supersaturation of In self-interstitials which was removed by dislocation loop formation that led to a supersaturation of P vacancies and to void formation.

D.Wittorf, A.Rucki, W.Jäger, R.H.Dixon, K.Urban, H.G.Hettwer, N.A.Stolwijk, H.Mehrer: Journal of Applied Physics, 1995, 77[6], 2843-5