THE STATE-OF-THE-ART OF ZNSE MELT GROWTH AND NEW STEPS TOWARDS TWIN-FREE BULK CRYSTALS

The present situation of ZnSe bulk growth is even. New steps for the c ontrol of the two main problems of melt-grown crystals are discussed: (i) the reduction of multitwins by seeding, and (ii) the maintenance o f stoichiometric composition using an in-situ Zn source during growth. ZnSe single crystals with diameters of 1 inch have been grown by the high-pressure vertical Bridgman method. Twin-free (100) wafers were pr epared for homoepitaxy. Structural and optical properties of such subs trates are investigated and discussed. An average etch pit density of 10(5) cm(-2) and a minimum full width at half maximum of 31 are sec ha ve been analysed.