Distribution of tellurium in melt-grown ZnSe(Te) crystals

• Published in: Journal of crystal growth 1999-02, Vol.197 (3), p.471-474
• Main Authors: Atroshchenko, L.V, Gal'chinetskii, L.P, Galkin, S.N, Ryzhikov, V.D, Silin, V.I, Shevtsov, N.I
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities in crystals; microstructure; Effective distribution coefficient of tellurium; Exact sciences and technology; Growth from melts; zone melting and refining; Impurities: concentration, distribution, and gradients; Impurity concentration, distribution, and gradients; Materials science; Methods of crystal growth; physics of crystal growth; Physics; Solid solution; Structure of solids and liquids; crystallography; Zinc selenide crystals
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(98)00963-4

The properties of semiconductor scintillation crystals are largely determined by the presence and distribution of the activator dopant. Influence of growth technological parameters (overheating Δ T, inert gas pressure P, crystallization rate V k) upon distribution of tellurium dopant was studied for ZnSe(Te) crystals grown by Bridgman technique in compression furnaces. Values of the “apparent” distribution coefficient of tellurium ( k Te) over crystal length were shown to be dependent on Δ T and the related value of charge carry-over (Δ m/ m 0). It was established that at Δ m/ m 0=12%, K Te=1; at Δ m/ m 01. This relationship is explained by assuming a competition between two processes affecting the distribution coefficient of tellurium: movement to the tail part in accordance with the phase diagram of the ZnSe–ZnTe pseudobinary system and thermal desorption of ZnTe due to its high volatility. Conditions required for preparation of ZnSe(Te) crystals of highly uniform composition are determined.