High Throughput Evaluation of Multi-Element, Multi-Functional Coatings for Improved Photocathodes

The development of efficient, stable photocathodes remains a primary materials challenge in the establishment of a scalable technology for artificial photosynthesis. The typical photoelectrode architecture consists of a semiconductor light absorber coated with a metal oxide that serves a combination of functions, including corrosion protection, electrocatalysis, light trapping, carrier transport, and elimination of deleterious surface recombination sites. We describe high throughput investigations of the variation in performance and photo-response of integrated photocathode libraries. The photocathode assembly libraries, for example, consist of uniform CuBi₂O₄ light absorbers coated with film libraries varying in composition and loading. Photoelectrode assemblies based on promising coating compositions and loadings were investigated in detail.