Electrodeposition of ZnO from Acetate Bath for Thermoelectric Devices

We attempted to form ZnO films with smooth surface for the application of thermoelectric micro-devices, using electrodeposition process. In order to reduce the defects of the films such as cracks and pits mainly caused by the gas evolution, the bath containing acetate in addition to nitrate ions was developed to reduce the gas evolution during the deposition. Using this bath, formation of ZnO, rather than Zn metallic films, was confirmed by Raman spectroscopy. The films had no cracks and the surface became smoother than those electrodeposited from the conventional nitrate-based bath. In order to fabricate the micro-devices, The ZnO was electrodeposited into the patterns with diameter of 200 μm. As a result, ZnO successfully filled the pattern keeping the smooth surface conditions, which demonstrated the applicability of the ZnO films to micro-device fabrication.