Photoelectrochemical stability improvement of cuprous oxide (Cu2O) thin films in aqueous solution

The photoelectrochemical (PEC) stability of cuprous oxide (Cu2O) is improved by using the p-type Cu2O films containing metallic copper inclusions, which are electrodeposited by controlling the concentration of sodium dodecyl sulfate in the plating solutions. The deposited Cu2O films change from n-type to p-type semiconductor with the increase of sodium dodecyl sulfate concentration to 1.70 mM. The PEC stabilities of p-type Cu2O films reach 99.23% without bias and 86.34% with bias, which are significantly higher than the n-type Cu2O films or the pure p-type Cu2O without copper inclusions. The crystal structure, morphology, and composition of the Cu2O films are characterized, and the effect of Cu inclusions on the PEC stability is interpreted through the energy band diagrams. Copyright (c) 2015 John Wiley & Sons, Ltd.