Two-step preparation and characterization of ZnO Core–Si shell coaxial nanorods

This study compares and analyzes the key characteristics of the ZnO core–Si shell coaxial nanorod (Si@ZnO NR) heterostructures that were grown on semi-insulating, (100)-oriented Si substrates at Si layer temperatures of 450, 500, 550 and 600 °C for optoelectronic device applications. The Si@ZnO NRs were prepared in two separate stages. Vapor-phase transport produced the ZnO NRs, whereas rapid thermal chemical vapor deposition formed the Si layers. Results obtained from X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and Raman tests indicate that the ZnO NRs were single crystals with a zincblende configuration. The findings also reveal that the Si layer was polycrystalline in nature, poly-Si, with a würtzite configuration. The present research is beneficial to the optoelectronic devices such as light-emitting diodes, solar cells and photodetectors in the UV–infrared range using the Si@ZnO coaxial nanostructures.