LOW SUPERSATURATION NUCLEATION AND CONTACTLESS GROWTH OF PHOTOREFRACTIVE ZNTE CRYSTALS

New photorefractive ZnTe crystals have been successfully grown by meth ods previously applied only for the growth of CdTe single crystals [K. Grasza, J. Crystal Growth 146 (1995) 65]. The main feature of this me thod lies in the novel procedure of self-seeding in conditions of perm anently low supersaturation, growth with no contact between the crysta l and ampoule wall, self-purification and improvement of stoichiometry of the source material during growth. Additionally, a new procedure o f lowering the optimal growth temperature was applied and an optimal g rowth rate with stable growth conditions was investigated. The ZnTe cr ystals had resistivity exceeding 10(8) Omega.cm. Photorefractive chara cterization was performed using the two-beam mixing technique, and the photorefractive gain in the range 0.63-1.5 mu m was measured.