Seeded-vapour-phase free growth and characterization of ZnTe single crystals

• Published in: Journal of crystal growth Vol. 214; pp. 870 - 874
• Main Authors: Korostelin, Yu.V, Kozlovsky, V.I, Shapkin, P.V
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2000
• Subjects: Cathodoluminescence; Vapour-phase growth; ZnTe substrate; ZnTe substrate; 71.55.Gs; Vapour-phase growth; 78.60.Hk; 81.10.Bk; 81.40.Ef; Cathodoluminescence
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(00)00213-X

A seeded-vapour-phase free growth (SVPFG) technique for obtaining large (40–50 mm in diameter) substrate-quality ZnTe single crystals is described. To provide high structural perfection of crystals, two main methods were applied. (i) The use of small area (1–2 cm 2) seeds in combination with a temperature regime that provides simultaneous tangential and normal growth of a crystal. This allowed to decrease an effect of seed quality on the structure of growing crystal. (ii) The use of a reverse temperature gradient between the seed and support pedestal. This allowed to avoid sticking a growing crystal to the pedestal and to decrease the contact area between them. The ZnTe crystals obtained were twin free. Ech pit density was about 10 4 cm −2. The full-width at half-maximum of the X-ray rocking curve was 18–22 arcsec. The specific resistance was 4–20 Ω cm. To remove Te precipitates observed in as-grown crystals, annealing in liquid Zn or Zn vapour was used. The removal of the Te precipitates correlates with decrease of acceptor related emission and increase of free exciton emission in the low-temperature cathodoluminescence spectra.