Temperature dependence on p-Cu2O thin film electrochemically deposited onto copper substrate

In this study, we attempted to quantitatively interpret the effect of electrodeposition temperature on Cu2O film's microstructure, optical and photoelectrochemical properties. Three deposit temperatures (35, 50 and 65 °C) were taken into consideration. Based upon our observations, a general trend was concluded. That is, Cu2O films deposited at lower temperature (35 °C) always possessed a high degree of preferential orientation, smaller pyramidal-like crystal size, high photolumminance and a higher carrier concentration. These properties made Cu2O films deposited at 35 °C a better photoelectrochemical performance with photocurrent density of −0.22 mA/cm2 bias −0.4 V vs. SCE. This value is about 35% higher than those Cu2O films deposited at higher temperatures. Observed higher photocurrent density is likely due to the intrinsic of a higher charge carrier concentration, and a lower resistance within Cu2O crystal and at Cu2O/electrolyte interface.