ZINC OXIDE (ZnO) AND BANDGAP ENGINEERING FOR PHOTOELECTROCHEMICAL SPLITTING OF WATER TO PRODUCE HYDROGEN

摘要

We report material synthesis, characterization, and photoelectrochemical (PEC) measurements to explore methods to effectively reduce the band gap of ZnO for the application of PEC water splitting. We find that the band gap reduction of ZnO can be achieved by N and Cu incorporation into ZnO. We demonstrate that heavy Cu-incorporation lead to both p-type doping and band gap significantly reduced ZnO thin films. The p-type conductivity in our ZnO:Cu films is clearly revealed by Mott-Schottky plots. We further have successfully synthesized ZnO:N thin films with various reduced band gaps by reactive RF magnetron sputtering. The band gap reduction and photoresponse with visible light for N- and Cu-incorporated ZnO thin films are demonstrated.