Surface Modification of SnO2 via MAPbI3 Nanowires for a Highly Efficient Non-Fullerene Acceptor-Based Organic Solar Cell.

Abstract

These days, organic-inorganic hybrid perovskites (OIHP) and non-fullerene acceptor (NFA) molecules are all at the frontiers of research and development in the domain of photovoltaics. A careful design and use of inorganic transparent metal oxides with wide band gaps as electron and hole transport layers are critically important for highly efficient and stable solar cells. As one of the most favorable electron transport materials, tin oxide (SnO2), which has been frequently utilized in highly efficient OIHP solar cells, is rarely seen in the application of NFA organic bulk heterojunction (BHJ) solar cells. To appropriately tailor an interface of SnO2 and an organic blend, while to make them compatible and useful may offer some opportunities for achieving higher efficiencies and longer lifetimes. In fact, there is still a lack of a method to solve the problem. Herein, a unique way is developed by implementing a surface decoration nanostructure such as low dimensional MAPbI3 perovskite nanowires (PeNWs) at the interface of SnO2 and the organic blend such as PBDB-T-SF:IT-4F. Such an interface functions well for the improvement of photovoltaic performance for the organic solar cell of the structure ITO(glass)/SnO2/PeNWs/PBDB-T-SF:IT-4F/MoO3/Ag. Experimental results indicate that the electron-hole dissociation, charge extraction, and photo-absorption ability of the organic solar cell can be improved significantly. The inside generation of the photocurrent is explored by the magneto-photocurrent method. Finally, the solar cell exhibits more than 80% power conversion efficiencies even after 20 days, which suggests the merits of having both SnO2 and PeNWs in the NFA-based organic solar cell.