Improved photovoltaic performance of polymer/Mn3O4 solar cells decorated with reduced graphene oxide

Exploring eco-friendly, low-cost, and chemically stable electron acceptor material is of great significance for the hybrid polymer-based solar cells (HPSCs). In this paper, Manganese tetroxide (Mn 3 O 4 ) nanoparticles with a unique tetragonal and hexagonal lamellar structure (4–8 nm) were successfully synthesized by solvothermal method, exhibiting an optical bandgap of 2.39 eV. The as-prepared Mn 3 O 4 nanoparticles were used as electron acceptors for HPSCs blended with a conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene](MEH-PPV) , and delivered a power conversion efficiency ( η ) of 0.73%. Notably, decorating Mn 3 O 4 with the reduced graphene oxide (rGO) to form rGO–Mn 3 O 4 composites significantly improved device efficiency by 38.4%, reaching a η of 1.01%. This enhancement is attributed to the extended electron lifetime facilitated by the formation of rGO–Mn 3 O 4 composite, which provides abundant exciton separation interfaces, thereby promoting efficient exciton separation and charge transfer. These findings offer a new strategy for designing high-performance, sustainable electron acceptor materials for HPSCs.