An experimental and theoretical exploration of the role of tri-element metal-nonmetal nanohybrids in photovoltaics

Inexpensive electrocatalysts with excellent catalytic activity as the counter electrodes (CEs) are crucial for the commercialization of solar cells. Herein, we report a unique rhombic dodecahedron framework of N-doped porous carbon loaded with 0.66 wt% Fe as a tri-element catalyst and its application as a CE in solar cells. Experimental and theoretical results reveal that the excellent catalytic activity is mainly attributed to the high ionic interaction between metal and nonmetal. A mesoporous structure can facilitate the penetration of the electrolyte and the involvement of internal active sites in the redox reaction. Consequently, solar cells constructed with tri-element metal-nonmetal nanohybrids provide an impressive power conversion efficiency of 8.06%, which is superior to that of Pt-based devices (7.93%). This is the highest efficiency reported for single Fe atom catalyst-based photovoltaics. The present work provides a new avenue for the exploration of earthabundant and efficient CE materials in photovoltaics.