Details

Autor(en) / Beteiligte

• Feng, Haohao
• Song, Xin
• Zhang, Ming
• Yu, Jiangsheng
• Zhang, Zhuohan
• Geng, Renyong
• Yang, Linqiang
• Liu, Feng
• Baran, Derya
• Tang, Weihua

Titel

Side chain engineering on dithieno[3,2-b:2,3-d]pyrrol fused electron acceptors for efficient organic solar cellsElectronic supplementary information (ESI) available: Materials synthesis and characterization, device fabrication and SCLC mobility measurement. See DOI: 10.1039/c8qm00669e

Erscheinungsjahr

2019-03

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Two novel dithieno[3,2- b :2,3- d ]pyrrol fused electron acceptors (FREAs) with branched alkyl side-chains have been developed. With 2-ethylhexyl and 2-butyloctyl introduced on the N-position of the pyrrol unit, the sidechain engineered acceptors ( INPIC-EH and INPIC-BO ) were evaluated for organic solar cells (OSCs) by comparison with our reference INPIC-4F bearing a linear octyl chain. The optoelectronic properties of the FREAs and their bulk-heterojunction (BHJ) with a PBDB-T donor for OSCs are systematically studied. All FREAs exhibit similar absorption spectra and energy levels. Notably, the charge dissociation process, charge mobility, and morphology of the BHJ films make a distinct difference. Consequently, the OSCs constructed with INPIC-EH and INPIC-BO delivered a power conversion efficiency (PCE) of 11.9% and 11.2%, lower than that of INPIC-4F devices (13.1%). The lower short-circuit current density ( J SC ) and fill factor (FF) of INPIC-EH and INPIC-OB based devices are attributed to unfavorable morphology of the active layers and more bimolecular recombination and unbalanced charge transport. Our investigation demonstrates that side-chain engineering on FREAs has a great impact on the morphology of blends and thus the photovoltaic properties of their OSCs. Two novel dithieno[3,2- b :2,3-d]pyrrol fused electron acceptors (FREAs) with branched alkyl side-chains have been developed.