Vapour growth and characterization of bulk ZnSe single crystals

Large (up to 60 mm in diameter) untwinned ZnSe single crystals have been grown in sealed quartz ampoules by seeded physical vapour transport and seeded chemical vapour transport with hydrogen. The dependence of structure perfection on the seed quality and its orientation, the source design, the gas filling of the growth ampoule and the temperature regime was researched. Selective chemical etching topography, X-ray diffraction rocking curve and cathodoluminescence studies are presented to characterize grown crystals. The influence of oxygen impurity on crystal emission and weakening of this influence in crystals grown in hydrogen was found. The results of crystal annealing in Zn vapour and Zn melt are discussed.