Introducing Low‐Cost Pyrazine Unit into Terpolymer Enables High‐Performance Polymer Solar Cells with Efficiency of 18.23%
Abstract
Recently, a random ternary copolymerization strategy has become a promising and efficient approach to develop high‐performance polymer donors for polymer solar cells (PSCs). In this study, a low‐cost electron‐withdrawing unit, 2,5‐bis(4‐(2‐ethylhexyl)thiophen‐2‐yl)pyrazine (PZ‐T), is incorporated into the polymer backbone of PM6 as the third component, and three D‐A1‐D‐A2 type terpolymers PMZ‐10, PMZ‐20, and PMZ‐30 are synthesized by the random copolymerization strategy, with the PZ‐T proportion of 10%, 20%, and 30%, respectively. The terpolymers exhibit downshifted highest occupied molecular orbital energy levels than PM6, which is beneficial for obtaining higher open‐circuit voltage (Voc) of the PSCs with the polymer as a donor. Importantly, the PSCs based on PMZ‐10:Y6 demonstrate efficient exciton dissociation, higher and balanced electron/hole mobilities, desirable aggregation, and high power conversion efficiency of 18.23%, which is the highest efficiency among the terpolymer‐based PSCs so far. The results indicate that the ternary copolymerization strategy with PZ‐T as the second A‐unit is an efficient approach to further improve the photovoltaic performance and reduce the synthetic cost of the D‐A copolymer donors.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 08, 2021
- Source ID
- 10.1002/adfm.202109271
Entities
People
- Can Zhu
- Harald Ade
- Indunil Angunawela
- Jinyuan Zhang
- Lei Meng
- Liuyang Zhou
- Shucheng Qin
- Yan Wan
- Yongfang Li
Organizations
- Beijing Normal University
- Institute of Chemistry
- North Carolina State University
- Office of Basic Energy Sciences
- Office of Science
- Soochow University
- United States Department of Energy
- University of Chinese Academy of Sciences