Photoelectrochemical water splitting by hybrid organic-inorganic systems: Setting the path from 2% to 20% solar-to-hydrogen conversion efficiency

Promoting solar fuels as a viable alternative to hydrocarbons calls for technologies that couple efficiency, durability, and low cost. In this work we elucidate how hybrid organic-inorganic systems employing hybrid photocathodes (HPC) and perovskite solar cells (PSC) could eventually match these needs, enabling sustainable and clean hydrogen production. First, we demonstrate a system comprising an HPC, a PSC, and a Ru-based oxygen evolution catalyst reaching a solar-to-hydrogen (STH) efficiency above 2%. Moving from this experimental result, we elaborate a perspective for this technology by adapting the existing models to the specific case of an HPC-PSC tandem. We found two very promising scenarios: one with a 10% STH efficiency, achievable using the currently available semiconducting polymers and the widely used methylammonium lead iodide (MAPI) PSC, and the other one with a 20% STH efficiency, requiring dedicated development for water-splitting applications of recently reported high-performing organic semiconductors and narrow band-gap perovskites.

Automated summary

Promoting solar fuels as a viable alternative to hydrocarbons requires technologies that combine efficiency, durability, and low cost. The combination of HPC and PSC systems shows potential for sustainable hydrogen production, with initial experiments achieving over 2% STH efficiency and the possibility of reaching 10% to 20% STH efficiency with further development of semiconductor and perovskite materials.