Electrochemical Deposition of Conformal Semiconductor Layers in Nanoporous Oxides for Sensitized Photoelectrodes

Abstract Nanoporous photoelectrodes with photoactive semiconductors have been investigated for various energy applications such as solar cells and photoelectrochemical cells, but the deposition of the semiconducting materials on the nanoporous electrodes has been very challenging due to pore clogging or complete pore filling. Here, we propose a band alignment model that explains the morphology of the electrochemically deposited semiconductor layer on the semiconducting nanoporous oxide electrode. Briefly, the coating material with a conduction band edge higher (i.e., more negative) than that of the electrode material forms a conformal coating, which maintains the initial nanoporous structure. As a result, a conformal CdSe layer can be electrodeposited onto TiO2 nanotubes, which can be used as a photoelectrode of a sensitized solar cell. The electron dynamics studies revealed that the CdS…