Enhanced Solar Photoelectrochemical Conversion Efficiency of ZnO:Cu Electrodes for Water-Splitting Application

Figure 2

Peak intensity of (002) plane in doped ZnO films with different concentrations of Cu doping. (a) ZnO, (b) 0.1 μM Cu²⁺, (c) 0.3 μM Cu²⁺, (d) 1.3 μM Cu²⁺, and (e) 26.4 μM Cu²⁺ concentrations.