Benzo[c][1, 2, 5]thiadiazole-fused pentacyclic small molecule acceptors for organic solar cells. (February 2021)

• Record Type: Journal Article
• Authors: Ming, Ruijie; Gao, Jinhua; Gao, Wei; Ning, Weimin; Luo, Zhenghui; Zhang, Fujun; Yang, Chuluo
• Is Part Of: Dyes and pigments. Volume 185(2021)Part B
• Publication Date: 2021-02
• Subjects: Organic solar cells -- A-DA′D-A architecture -- Small molecular acceptors -- End group; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2020.108970
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: Recently, A-DA′D-A-type small molecular acceptors (SMAs) with benzo [ c ][1, 2, 5]thiadiazole (BT)-fused central cores have shown tremendous progress in organic solar cells (OSCs). In this work, two new BT-fused pentacyclic core based SMAs, namely BTT-4F and BTTCN-Cl, were designed and synthesized. Compared to BTT-4F, BTTCN-Cl not only delivers a reduced bandgap but an elevated lowest unoccupied molecular orbital (LUMO) energy level, which leads to a higher open-circuit voltage ( V OC ) and thus a lower energy loss in PM6:BTTCN-Cl-based device. However, PM6:BTT-4F-based OSCs achieves a significantly higher power conversion efficiency (PCE) (10.03%) than that of BTTCN-Cl-based OSCs (6.56%) due to its higher short-circuit density ( J SC ) and fill factor (FF). More favorable morphology accompanying with higher and more balanced hole/electron mobilities was obtained in PM6:BTT-4F active layer, which well accounts for the high PCE in BTT-4F-based OSCs. Highlights: Two novel SMAs based on fused pentacyclic benzo [ c ] [1, 2, 5]thiadiazole core were synthesized and developed. The two SMAs exhibit intense light absorption in the range of 600–800 nm. A high V OC of 0.90 V was obtained. A high PCE of 10.03% was achieved in organic solar cells.