Applied Surface Science, Vol.489, 269-277, 2019
Luminescence properties of ZnO-M heterostructures fabricated by galvanic-submerged photosynthesis of crystallites
By adapting hetero-nanostructures in optoelectronic device, a prominent luminescence characteristic can be obtained. The challenge is to engineer the band bending if a semiconducting surface gets contact with a metal. A galvanic replacement method is versatile for bimetallic hetero-nanostructures synthesis. However, the nanostructures morphologies can be varied depending on the metals pair or their supporting template. In this study, we demonstrate a facile 1-D ZnO nanorods (NRs) growth fabricated by galvanic replacement reactions. Without using bimetallic solution, the galvanic replacement reaction was implemented by joining Zn metal to Au, Pt, Ag, Cu, W, and Ni metals substrate. The luminescence properties of ZnO NRs were characterized by photoluminescence (PL) and cathodoluminescence in scanning transmission electron microscopy (STEM-CL). Based on PL analysis result, oxygen vacancy (V-O) was responsible for the visible light region emission in all ZnO-M samples. Then, STEM-CL analysis highlighted the presence of zinc interstitial (Zn-i) at the interface of ZnO-M. Due to band bending, interaction between V-O and Zn-i resulted the formation of zinc antisite (Zn-O) at the interface. There was no shift in visible light emission of the NRs due to Fermi-level pinning. The findings will be useful for future large-scale synthesis and engineering of hetero-nanostructures luminescent devices.
Keywords:ZnO heterostructures;Submerged photosynthesis;Nanorods;Galvanic replacement;Photoluminescence;Cathodoluminescence