Tuning of optical band gap and photoluminescence behaviours of 1D-ZnO decorated with ZrO2 (ZnO-NRs/ZrO2 core-shell) nanostructured materials by pulse laser deposition technique

The one-dimensional (1D) ZnO-NRs/ZrO2 core-shell nanostructures were prepared by coating thin ZrO2 layers on the surface of 1D-ZnO-NRs using a novel pulsed laser deposition (PLD) technique at different temperatures and varying oxygen pressure during the deposition process. Morphological and structural characterizations confirm the uniform deposition of 1D-ZnO-NRs by the deposited ZrO₂ shell. It is found that the photoluminescence (PL) of ZnO-NRs/ZrO2 core/shell nanostructures is strictly dependent on their optical band gaps, and the PL intensity at ultraviolet (UV) emission progressively enhanced in comparison to bare 1D-ZnO-NRs. This significant enhancement of the UV emission mechanism can be attributed to the effective carrier confinement effect, defects, and surface passivation of the type-I core shell nanostructure, which could be very useful for future optoelectronic device-based applications.