An investigation was made of unintentional impurities and intrinsic defects in samples which had been grown by using metalorganic vapor-phase epitaxy. In the case of ZnSe which had been grown under optimal conditions on GaAs, high electron mobilities and low background carrier concentrations were found. Changes in the growth parameters led to the appearance of donor-acceptor pair recombinations at 2.72eV. A line at 2.55eV was not observed in samples that had been grown at temperatures below 420C, but was generated by high-temperature treatments. The emission was related to extended lattice defects, such as dislocations, that were created by strain. No emission at 2.25 to 2.45eV arose from as-grown samples, but could be generated by high-temperature treatment in H, Zn, or Se atmospheres. It was concluded that this defect was not due only to an extrinsic impurity.

M.Heuken, J.Söllner, F.E.G.Guimarães, K.Marquardt, K.Heime: Journal of Crystal Growth, 1992, 117, 336-40