Enhanced device performance via interfacial engineering in non-fullerene acceptor based organic solar cells

Abstract

Introduction of interface layers can maximize the performance of certain organic solar cells. We demonstrate that high efficiency non-fullerene acceptor based solar cells can be further improved with the insertion of PC70BM as an interlayer between the electron transport layer and the active layer. The combination of ZnO and PC70BM layers between a cathode and a bulk heterojunction active layer appears to serve as a better selective contact by reducing charge transport barrier and recombination. The enhanced short-circuit current density (JSC) is characterized by a low series-resistance (<2 ω cm2), improved charge collection efficiency, and power conversion efficiency. These features are reflected in impedance spectroscopy and electrical noise measurements and provide a route for large-area organic solar cells.