A Room-Temperature Processable PDI-Based Electron-Transporting Layer for Enhanced Performance in PDI-Based Non-Fullerene Solar Cells

In this study, it is demonstrated that a facile room-temperature processed amine functionalized perylene-diimide (PDIN) can function as an efficient electron-transporting layer (ETL) to enhance the photovoltaic performance of inverted PDI-based non-fullerene solar cells. It is showed that the PDIN ETL possesses respectable mobilities and interfacial doping capability to the PDI-based acceptors to facilitate the charge transport and extraction in the devices. Moreover, it can modulate the morphological evolution of the bulk-heterojunction (BHJ) atop to result in a more crystalline, face-on orientation because of its improved compatibility to PDI-based acceptors. Consequently, the PDIN ETL enables the derived devices to have 10% higher power conversion efficiency (PCE) than the reference device. In addition, the PDIN can also be used as a surface modifier on ZnO to result in a approximate to 14% enhanced PCE than that of the pristine ZnO-based device. This study shows the feasibility of modulating the BHJ of non-fullerene organic photovoltaics by rationally selected ETLs to facilitate exciton dissociation and collection of the devices.