Vapor growth and characterization of ZnSeTe solid solutions

Abstract Six ZnSe 1−x Te x crystals were grown by the physical vapor transport technique. For each of the source material compositions, x =0.10, 0.20 and 0.30, two crystals were grown — one under horizontal and the other under vertical stabilized configurations. The axial and radial compositional uniformity were determined by precision density measurements, wavelength dispersive X-ray spectroscopy (WDS) and optical transmission mappings. The measured radial ZnTe content was quite uniform for all grown crystals except the horizontally grown crystal for x =0.30. WDS results on this crystal indicated a core with uniform ZnTe content, about 0.38, surrounded by a thin region of high ZnTe content with x =0.8. This feature was confirmed by the SEM back scattering electron images. For the three source compositions the axial compositional variations for the vertically grown crystals were more uniform than those for the horizontally grown crystals. The measured compositions in the crystals grown from source composition of x =0.10 suggest that the transport mechanism in the system cannot be interpreted by a simple one-dimensional diffusion limited model.