Integrated Solar‐Driven Device with a Front Surface Semitransparent Catalysts for Unassisted CO ₂ Reduction

Monolithic integrated photovoltaic-driven electrochemical (PV-EC) artificial photosynthesis is reported for unassisted CO2 reduction. The PV-EC structures employ triple junction photoelectrodes with a front mounted semitransparent catalyst layer as photocathode. comprised of an array microscale triangular metallic prisms that redirect incoming light toward open areas the photoelectrode to reduce shadow losses. Full wave electromagnetic simulations prism (PA) structure guide optimization geometries and length scales. An device constructed Ag covering 35% surface area. experimental has close 80% transmittance catalytic area equivalent 144% glass substrate Experimentally this photocathode demonstrates direct solar-to-CO conversion efficiency 5.9% 50 h stability. Selective electrodeposition Cu catalysts onto allows higher value products enabling demonstration solar-to-C2+ product 3.1%. This design featuring have on cell general solution loss by shadowing metal catalysts, opens route development based scalable approach.