Investigation of the transition range in seeded vapour grown ZnSe crystals

Prerequisite for the growth of large area single crystals are exactly (111)Se orientated seeds. For both used growth methods, seeded physical vapour transport (SPVT) and seeded chemical vapour transport (SCVT), an improved crystal quality can be achieved. In SCVT crystals, optically active deep level (DL) defects dominate mainly due to the self activated (SA)-centre. The transition range width was more than three times that of SPVT material, but in the bulk the concentration of linear defects is lower. Strong exciton luminescence and decreasing DL emission were found in the bulk of SPVT crystals. The decision what method should be used for optimal substrate performance has to be drawn after manufacturing light emitting devices by epitaxial methods.