Rapid Screening Method for the Viability of Emerging Photoelectrode Materials and Compositions

Rapid and facile screening methods are needed for the assessment of viability of novel photoelectrode materials and synthesis methods. We developed a combined experimental-numerical screening method that allows for the rapid transport assessment of such materials. The method requires as an input incident photon-to-current efficiency (IPCE) measurements of a material at two or more wavelengths and calculates the diffusion length, optical losses, bulk recombination losses, space charge region losses, and surface losses. The diffusion optical depth, defined as the product of the absorption coefficient and the diffusion length at 500 nm, was used to quantify the viability of the materials. The method was validated using planar Cu₂O water-splitting photoelectrodes [1]. Subsequently, it was applied to known and emerging planar water-splitting photoelectrodes made of Cu₂O, Si, Fe₂O₃, BiVO₄, Cu₂V₈O₃, CuFeO₂, and In_xGa_1-xN [2], and to nanostructured photoelectrodes made of Fe₂O₃ and LaTiO₂N. We propose a benchmark that can be used to provide guidance on the viability of these known and emerging material and their specific synthesis methods. The validated tool can be used to screen the viability of photoelectrode materials and structures in order to support and guide material research and development. This tool is not restricted to water-splitting reaction but can be applied to any photoelectrochemical reaction and for the in-situ assessment of the degradation of these materials.<br/><b>References</b><br/>[1] Y. Gaudy, S. Haussener, <i>Journal of Physical Chemistry C</i>, 10.1021/acs.jpcc.9b04102, 2019.<br/>[2] Y. Gaudy, Z. Gacevic, S. Haussener, <i>APL Materials</i>, 10.1063/5.0007034, 2020.