Morphological and Optical Characteristics of Transition Metal Doped PVT Grown Zinc Selenide Single Crystal

An experimental study on the absorption, emission, crystal quality, and morphological characteristics of the transition metal doped zinc selenide (ZnSe) crystals is performed. This study focuses on the effect of dopant and thermal convection on crystal characteristics. Two ZnSe crystals, one doped with Fe2+ and the other with Cr2+, are grown using the physical vapor transport method. The bulk crystal samples are further divided into localized zones and overall crystallinity is evaluated using optical transparency, scanning electron microscopy, and X‐ray diffraction analyses. Gross defects, such as large precipitates, inclusions and voids, are not observed. The radial segregation and its effect on morphology and optical fluorescence and emission are studied for both doped crystals using different spots along the radius for both crystals. The absorption and emission properties are investigated and the results are discussed in terms of the energy levels from which the optical transitions occur. Bulk zinc selenide (ZnSe) crystals, doped with Fe2+ and Cr2+ are grown by physical vapor transport method for industrial applications. Optical absorption, fluorescence, and emission properties depend on morphology, radial segregation, and point defects of these crystals. The Cr2+ ion is predicted to give more favorable spectroscopic properties than the Fe2+ ion when incorporated into the ZnSe matrix.