Preparation and characterization of Zn_xCd_1−xS ternary alloys micro/nanostructures grown by thermal evaporation

Ternary alloy zinc cadmium sulfide (Zn_xCd_1−xS) micro/nanostructures were prepared onto various substrates using a thermal evaporation method. Morphological, structural, and optical properties were found to depend on growth temperature and substrate type. Zn_xCd_1−xS microparticles and flower-like structures were grown onto ITO-glass and Si(100) substrates at 520 °C. Microrods and nanosheets were formed on alumina and Si(100) substrates at 900 °C, as shown in scanning electron microscopy images. X-ray diffraction patterns confirmed that all prepared samples had a high-quality wurtzite (hexagonal) structure. The prepared samples emitted two bands, namely, a sharp one located in the green region corresponding to the near band edge and a broad band in the yellow region resulting from deep-level transition. The green photoluminescence peak location of the prepared samples blue shifted compared with the optical bandgap of bulk CdS, indicating that the prepared Zn_xCd_1−xS possessed a greater optical bandgap than that of CdS because of the Zn ratio. (paper)