April 6-10, 2015 | San Francisco
Meeting Chairs: Artur Braun, Hongyou Fan, Ken Haenen, Lia Stanciu, Jeremy A. Theil
A practical solar water splitting device that can produce H2 at a cost less than PV + electrolysis is difficult to envision without it possessing a simple construction that employs widely available materials and inexpensive processing techniques. A tandem cell consisting of 2 solution-processed photoelectrodes (photoanode/photcathode) can reasonably reach this goal. While n-type oxide semconductors have been established as viable photoanode materials, cheap and stable p-type photocathodes are less developed. In this presentation our gorups&’ progress in the development of solution-processed stable photocathodes is presented and their application toward overall photoelectrochemical water splitting tandem cells is demonstrated. Three classes of promising materials are discussed: copper-based oxides in the delafossite phase, ternary and quaternary chalcogenides, and 2D transition metal chalcogenides. In each case the challenges to maximize photogenerated charge collection in thin films prepared by solution-based deposition approaches are highlighted and the use of bottom-up nanostructuring to gain insight into routes for improvement and overcome these challenges are established. The optimization of these materials for solar water reduction using overlayers and catalysts, and the stability under reasonable operation conditions are addressed. Routes to improve the unassisted and overall solar water splitting performance in tandem cells with commonly used oxide photoanodes are finally outlined.