Temperature dependence on p-Cu ₂ O thin film electrochemically deposited onto copper substrate

In this study, we attempted to quantitatively interpret the effect of electrodeposition temperature on Cu ₂ O 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, Cu ₂ O 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 Cu ₂ O films deposited at 35 °C a better photoelectrochemical performance with photocurrent density of -0.22 mA/cm ² bias -0.4 V vs. SCE. This value is about 35% higher than those Cu ₂ O 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 Cu ₂ O crystal and at Cu ₂ O/electrolyte interface.