Two‐Dimensional Conjugated Benzo[1, 2‐b:4, 5‐b′]diselenophene‐Based Copolymer Donor Enables Large Open‐Circuit Voltage and High Efficiency in Selenophene‐based Organic Solar Cells. Issue 20 (12th September 2021)

• Record Type: Journal Article
• Authors: Liu, Yan‐Qiang; Zhi, Hong‐Fu; Bai, Hai‐Rui; Jiang, Zhao; Wan, Shi‐Sheng; Jiang, Mengyun; Mahmood, Asif; Yang, Can; Sun, Shuo; An, Qiaoshi; Wang, Jin‐Liang
• Is Part Of: ChemSusChem. Volume 14:Issue 20(2021)
• Page Start: 4454
• Page End: 4465
• Publication Date: 2021-09-12
• Subjects: conjugated polymers -- copolymers -- heterocycles -- organic solar cells -- selenium; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202101232
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: A two‐dimensional electron‐rich fused‐ring moiety (ClBDSe) based on benzo[1, 2‐ b :4, 5‐ b ′]diselenophene is synthesized. Three copolymers (PBDT−Se, PBDSe−T, and PBDSe−Se) are obtained by manipulating the connection types and number of selenophene units on the conjugated main chains with two 2D fused‐ring units and two different π‐bridges, respectively. In comparison with PBDT−Se and PBDSe−Se, PBDSe−T with benzo[1, 2‐ b :4, 5‐ b ′]diselenophene unit and thiophene π‐bridge exhibits the deepest HOMO energy level and the strongest crystallinity in neat films. The PBDSe−T:Y6 blend film exhibits the best absorption complementarity, the most distinctive face‐on orientation with proper phase separation, the highest carrier mobilities, and the lowest charge recombination among three blend films. Finally, the PBDSe−T:Y6‐based device delivers an impressive power conversion efficiency (PCE) of 14.50 %, which is higher than those of PBDT−Se:Y6 and PBDSe−Se:Y6. Moreover, a decent open‐circuit voltage ( V oc ) of 0.89 V with a remarkably small energy loss of 0.44 eV is achieved for PBDSe−T:Y6. The efficiency of 14.50 % is the highest value for selenophene‐containing copolymer‐based binary organic solar cells (OSCs). This study provides evidence that introduction of 2D‐benzo[1, 2‐ b :4, 5‐ b ′]diselenophene as a fused electron‐rich unit with π‐bridging into copolymeric donors is a valid strategy for providing high V oc and excellent PCE simultaneously in selenophene‐based OSCs. Abstract : Introduction of two‐dimensional conjugated benzo[1, 2‐b:4, 5‐b′]diselenophene as a fused electron‐rich unit with π‐bridging connections into copolymeric donors is an effective strategy for providing high open‐circuit voltage and excellent power conversion efficiency (PCE) simultaneously in selenophene‐based organic solar cells (OSCs). The optimum PCE of 14.50 % is the highest value for selenophene‐containing copolymer‐based binary OSCs.