Hydrothermal synthesis of improved ZnO crystals for epitaxial growth of GaN thin films

Autor: Evgeniya V. Kortunova, N.I. Leonyuk, Natalia G. Nikolaeva, Thomas F. Kuech, E. A. Volkova, V. V. Maltsev, Peter P. Chvanski, Elizaveta V. Koporulina
Rok vydání: 2007
Předmět:
Zdroj: Journal of Materials Science. 43:2336-2341
ISSN: 1573-4803
0022-2461
DOI: 10.1007/s10853-007-2036-5
Popis: ZnO single crystals with thickness up to 12 mm, 2 inches in “diameter” and weight of about 150 g have been grown from KOH, NaOH, and K2CO3 based hydrothermal solutions on the seeds of (0001) orientation. The addition of LiOH up to 3.0–4.5 mol/L allowed to decrease the growth rate of ZnO crystals along the 〈0001〉 crystallographic direction. For positive and negative monohedra, it was achieved 0.12 and 0.01 mm/day, respectively, at temperature 340 °С and ΔТ = 10 °С. The best ZnO etching agent was found to be the solutions 25 mol% HCl + 3 mol% NH4F at room temperature, and etching time 5 min. The dislocation density of ZnO crystals varied from 240 cm−2 to 3,200 cm−2 in the case of growth rates 0.04 mm/day to 0.11 mm/day, respectively. It was also found that ZnO crystals grown are stable in air, oxygen, nitrogen, and argon atmosphere as well as in vacuum at the temperatures up to 1,000 °C under thermal treatment during 4 h.
Databáze: OpenAIRE
Externí odkaz: