title: Photoelectrochemical behavior of hierarchically structured Si/WO3 core-shell tandem photoanodes.
abstract: WO3 thin films have been deposited in a hierarchically structured core-shell morphology, with the cores consisting of an array of Si microwires and the shells consisting of a controlled morphology WO3 layer. Porosity was introduced into the WO3 outer shell by using a self-assembled microsphere colloidal crystal as a mask during the deposition of the WO3 shell. Compared to conformal, unstructured WO3 shells on Si microwires, the hierarchically structured core-shell photoanodes exhibited enhanced near-visible spectral response behavior, due to increased light absorption and reduced distances over which photogenerated carriers were collected. The use of structured substrates also improved the growth rate of microsphere-based colloidal crystals and suggests strategies for the use of colloidal materials in large-scale applications.
authors.affiliation: Division of Chemistry and Chemical Engineering, Beckman Institute, Kavli Nanoscience Institute, and the Joint Center for Artificial Photosynthesis, California Institute of Technology , 210 Noyes Laboratory, Pasadena, California 91125, United States.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Coridan
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Arpin
authors.forename: Bruce S
authors.initials: BS
authors.lastname: Brunschwig
authors.forename: Paul V
authors.initials: PV
authors.lastname: Braun
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Lewis