Supersaturation control in crystal growth of II–VI compounds from the vapour

• Published in: Journal of crystal growth 1974-01, Vol.21 (2), p.219-226
• Main Authors: Tempest, P.A., Ballentyne, D.W.G.
• Format: Article
• Language: English
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/0022-0248(74)90008-6

Large single crystals of CdS and ZnS have been grown by a modified Piper and Polich method in argon atmosphere. The best quality boules were obtained when the growth rate was limited by the diffusion rather than by the condensation of the vapours at the crystal surface. A theoretical approach to the diffusion of the vapours and their condensation at the crystal surface shows the supersaturation to be a function of the transport resistance (determined by the temperatures of the source and seed, vapour stoichemetry, and diffusion constants) and the surface resistance (determined by the surface temperature and the activatio energy barrier). The conditions for diffusion-limited growth, with the vapour slightly supersaturated, and condensation- limited, with the vapour highly supersaturated, are determined. An important intermediate region where neither the transport nor the surface resistance is dominant is also shown to exist.