Ternary Polymer Solar Cells Facilitating Improved Efficiency and Stability
Yingying Dong1, Yan Zou1, Jianyu Yuan2, Hang Yang1, Yue Wu1, Chaohua Cui1,*（崔超华）, and Yongfang Li1,3
1Laboratory of Advanced Optoelectronic Materials College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123, China
2 Key Laboratory for Carbon-Based Functional Materials & Devices Institute of Functional Nano & Soft Materials (FUNSOM) Soochow University Suzhou 215123, China
3CAS Research/Education Center for Excellence in Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Beijing 100190, China
Adv. Mater. 2019, 1904601
The use of a ternary active layer offers a promising approach to enhance the power conversion efficiency (PCE) of polymer solar cells (PSCs) via simply incorporating a third component. Here, a ternary PSC with improved efficiency and stability facilitated by a new small molecule IBC‐F is demonstrated. Even though the PBDB‐T:IBC‐F‐based device gives an extremely low PCE of only 0.21%, a remarkable PCE of 15.06% can be realized in the ternary device based on PBDB‐T:IE4F‐S:IBC‐F with 20% IBC‐F, which is ≈10% greater than that (PCE = 13.70%) of the control binary device based on PBDB‐T:IE4F‐S. The improvement in the device performance of the ternary PSC is mainly attributed to the enhancement of fill factor, which is due to the improved charge dissociation and extraction, suppressed bimolecular and trap‐assisted recombination, longer charge‐carrier lifetime, and enhanced intermolecular interactions for preferential face‐on orientation. Additionally, the ternary device with 20% IBC‐F shows better thermal and photoinduced stability over the control binary device. This work provides a new angle to develop the third components for building ternary PSCs with enhanced photovoltaic performance and stability for practical applications.