Effect of copper evolution on photoelectric properties of ZnO/Cu/ZnO hybrids

ZnO/Cu/ZnO hybrids were prepared by sputtering method to systematically explore the effect of copper evolution on their photoelectric properties. The observed interfacial interaction between ZnO and Cu is indeed weak vdW rather than covalent, and their structural and photoelectric properties are strongly related to the Cu layer thicknesses. Moreover, the resistivity and optical transmittance of these hybrids gradually decrease as Cu thickness increases. The resistivity and peak transmittance at the optimum copper layer thickness (about 7 nm) are 1.78 × 10⁻⁴ Ω cm and 83%, respectively. These results can help insights into the interaction of ZnO-based sandwich structure composites, and pave the way for developing high-performance transparent conducting oxide (TCO) electrodes.