Materials properties of ZnO/diamond-like carbon (DLC) nanocomposite fabricated with different source of targets

Zinc oxide/diamond-like carbon (ZnO/DLC) nanocomposite films were grown using two different composite targets, namely zinc/carbon (Zn/C) and zinc oxide/carbon (ZnO/C) targets with pulsed laser deposition technique as a comparison. In both cases, transmission electron microscopy (TEM) confirmed that ZnO nanoclusters were formed embedded in an amorphous carbon matrix. Interestingly, only films obtained from ZnO/C targets yielded monochromatic UV (~ 378 nm) emission peaks in photoluminescence. X-ray photoelectron spectroscopy (XPS) revealed that a higher fraction of O2− ions in oxygen-rich ZnO was formed in ZnO/DLC films prepared by ZnO/C targets but with a consistently lower sp3 content. As such, the hardness of the films decreased. However, the formation of SiC due to the deposition process improved the adhesion strength of the films, as evidenced by experimental data.

► ZnO/DLC films can be fabricated using Zn/C and ZnO/C targets. ► Only ZnO/C targets yielded ZnO/DLC films with improved adhesion strength and UV emission. ► Higher sp3 with lower SiC content were observed on films fabricated with ZnO/C target. ► This was due to the higher ion density and energy absorbed in the deposition with ZnO/C targets.