Design of a Rigid Scaffold Structure toward Efficient and Stable Organic Photovoltaics

Abstract

Summary Organic photovoltaics (OPVs) have attracted considerable attention in recent years. Most reported strategies are from the perspective of the active layers to control the morphology of the donor/acceptor blend, with few methods focusing on modifying the transporting layers. Here, we develop a facile method to enhance both the thermal stability and efficiency of OPVs simultaneously from the perspective of the electron-transporting layer (ETL). Compared with traditional planar ETLs used in OPVs, our mesoporous ETL is designed to serve as a rigid scaffold to inhibit polymer diffusion upon heating. Furthermore, this structure creates more surface-area contact between the active layer and the ETL, potentially enhancing charge-extraction efficiency. As a result, the power-conversion efficiency (PCE) with this structure was enhanced by 11% relative to the planar structure. After being subjected to thermal stability test, the PCE of the mesoporous structure retained 69% of its original value.