標題: A chlorinated nonacyclic carbazole-based acceptor affords over 15% efficiency in organic solar cells
作者: Chen, Tsung-Wei
Peng, Kuan-Lin
Lin, You-Wei
Su, Yi-Jia
Ma, Ko-Jui
Hong, Ling
Chang, Chia-Chih
Hou, Jianhui
Hsu, Chain-Shu
交大名義發表
應用化學系
National Chiao Tung University
Department of Applied Chemistry
公開日期: 21-Jan-2020
摘要: In this contribution, a dithienocyclopentacarbazole (DTC)-based and two dithieno[3,2-b]thiophenecyclopentacarbazole (DTTC)-based non-fullerene acceptors (NFAs) named DTC-4F, DTTC-4F and DTTC-4Cl were exploited to elucidate the effects of conjugation extension and end group chlorination. DTTC-4F was designed through conjugation extension on the basis of DTC-4F by fusing one additional thiophene on both flanks of the heptacyclic DTC core, generating the nonacyclic DTTC core. Compared with DTC-4F, DTTC-4F features up-shifted energy levels, red-shifted absorption and enhanced pi-pi interaction. PM6:DTTC-4F exhibits a decent PCE of 13.89% with a V-OC of 0.95 V, a J(SC) of 21.66 mA cm(-2) and a FF of 67.60%. Although DTTC-4F affords a reduced FF compared to DTC-4F, a DTTC-4F-based device delivers a higher PCE than DTC-4F-based devices due to the extended absorption range of DTCC-4F in comparison with DTC-4F. Since chlorinated NFAs are known to possess stronger pi-pi interaction than fluorinated NFAs, DTTC-4Cl was therefore synthesized by end-capping DTTC core with 2Cl-IC groups instead of 2F-IC groups. Moreover, DTTC-4Cl demonstrates a red-shifted absorption in comparison with DTTC-4F, which is beneficial for light-harvesting. Overall, PM6:DTTC-4Cl affords an outstanding PCE of 15.42% with a V-OC of 0.92 V, a J(SC) of 22.64 mA cm(-2) and a FF of 74.04%, which is the record PCE observed in carbazole-based NFAs.
URI: http://dx.doi.org/10.1039/c9ta12605h
http://hdl.handle.net/11536/153757
ISSN: 2050-7488
DOI: 10.1039/c9ta12605h
期刊: JOURNAL OF MATERIALS CHEMISTRY A
Volume: 8
Issue: 3
起始頁: 1131
結束頁: 1137
Appears in Collections:Articles