MoSe2 and WSe2 shell morphology control via temperature optimization during two-step growth of ZnSe-based core-shell nanowires

Achieving uniform and controlled transition metal dichalcogenide (TMD) shell growth on nanowires (NWs) remains a key challenge, limiting the development of high-quality core-shell heterostructures for optoelectronic and photocatalytic applications. In this work, the fabrication of ZnSe–MoSe₂ and ZnSe–WSe₂ core-shell NWs was successfully demonstrated. ZnSe NWs were grown via the vapour-liquid-solid growth mechanism, while TMD (MoSe₂ or WSe₂) shells were formed through a two-step process of sacrificial oxide layer deposition via magnetron sputtering followed by selenization process in a chemical vapour transport reactor. As-grown nanostructures were characterized using X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and photoluminescence spectroscopy. It was observed that the TMD shell morphology can be controlled through the selenization process temperature optimization, which arises due to different growth mechanisms discussed here. The studied trends could be further extended to other semiconductor NW and TMD core-shell heterostructure growth, offering promising avenues for advanced nanoscale applications.