Side chain engineering on dithieno[3,2-b:2,3-d]pyrrol fused electron acceptors for efficient organic solar cells

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

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

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 (JSC) 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.
Original languageEnglish (US)
Pages (from-to)702-708
Number of pages7
JournalMaterials Chemistry Frontiers
Volume3
Issue number4
DOIs
StatePublished - 2019

Fingerprint Dive into the research topics of 'Side chain engineering on dithieno[3,2-b:2,3-d]pyrrol fused electron acceptors for efficient organic solar cells'. Together they form a unique fingerprint.

Cite this