Synthesis, Characterization, and Electronic Properties of ZnO/ZnS Core/Shell Nanostructures Investigated Using a Multidisciplinary Approach

ZnO/ZnS core/shell nanostructures, which are studied for diverse possible applications, ranging from semiconductors, photovoltaics, and light-emitting diodes (LED), to solar cells, infrared detectors, and thermoelectrics, were synthesized and characterized by XRD, HR-(S)TEM, and analytical TEM (EDX and EELS). Moreover, band-gap measurements of the ZnO/ZnS core/shell nanostructures have been performed using UV/Vis DRS. The experimental results were combined with theoretical modeling of ZnO/ZnS (hetero)structures and band structure calculations for ZnO/ZnS systems, yielding more insights into the properties of the nanoparticles. The ab initio calculations were performed using hybrid PBE0 and HSE06 functionals. The synthesized and characterized ZnO/ZnS core/shell materials show a unique three-phase composition, where the ZnO phase is dominant in the core region and, interestingly, the auxiliary ZnS compound occurs in two phases as wurtzite and sphalerite in the shell region. Moreover, theoretical ab initio calculations show advanced semiconducting properties and possible band-gap tuning in such ZnO/ZnS structures.

Automated summary

ZnO/ZnS core/shell nanostructures were synthesized and characterized using XRD, HR-(S)TEM, and analytical TEM (EDX and EELS), and their band-gap measurements were performed using UV/Vis DRS. The experimental results were combined with theoretical modeling and calculations to gain more insights into the properties of the nanoparticles. The synthesized materials showed a unique three-phase composition, with ZnO dominating the core region and ZnS occurring in two phases (wurtzite and sphalerite) in the shell region. The theoretical calculations demonstrated advanced semiconducting properties and the potential for band-gap tuning in ZnO/ZnS structures.