Regulation of ZnO Nanorod Arrays Performance by ZnS Shell Layer Using PLD Technique

Abstract Vertically aligned ZnO@ZnS core-shell nanorod arrays were fabricated by pulsed laser deposition (PLD) of ZnS shell layers onto hydrothermally grown ZnO nanorods. X-ray diffraction (XRD) results verify well-defined crystallinity with characteristic ZnO (002) and β-ZnS (111) diffraction peaks. Scanning electron microscopy (SEM) observations reveal well-oriented vertical nanorod arrays, where ZnS encapsulation increases the nanorod diameter, further confirmed by energy-dispersive X-ray spectroscopy (EDS). Optical measurements demonstrate improved visible-light transmittance for the core-shell structure relative to pure ZnO nanorods. Photoluminescence (PL) spectra display three emission bands centered at ~380 nm (ultraviolet), ~450 nm (blue), and ~540 nm (green). Compared with bare ZnO nanorods, ZnO@ZnS core-shell arrays exhibit strengthened near-band-edge ultraviolet emission and suppressed deep-level defect emission, accompanied by the generation and reinforcement of blue emission. Such structural modulation endows the ZnO@ZnS core-shell nanorods with great potential for high-performance optoelectronic applications.