title: Nonfullerene-Acceptor All-Small-Molecule Organic Solar Cells Based on Highly Twisted Perylene Bisimide with an Efficiency of over 6.
abstract: Two twisted singly linked perylene bisimide (PBI) dimers with chalcogen bridges in the PBI cores, named C4,4-SdiPBI-S and C4,4-SdiPBI-Se, were synthesized as acceptors for nonfullerene all-small-molecule organic solar cells (NF all-SMSCs). A moderate-band-gap small-molecule DR3TBDTT used as the electron donor displayed complementary absorption with C4,4-SdiPBI-S and C4,4-SdiPBI-Se. It was found that solvent-vapor annealing (SVA) played a critical role in the photovoltaic performance in NF all-SMSCs, which improves the crystallinity of the donor and acceptors, promotes the proper phase segregation domain size, and therefore enhances charge transport. The power conversion efficiencies (PCEs) of NF all-SMSC devices based on DR3TBDTT/C4,4-SdiPBI-S and DR3TBDTT/C4,4-SdiPBI-Se increased from 2.52% to 5.81% (JSC= 11.12 mA cm-2, VOC= 0.91 V, and FF = 57.32%) and from 2.65% to 6.22% (JSC= 11.55 mA cm-2, VOC= 0.92 V, and FF = 58.72%), respectively, after exposure to chloroform vapor. The best efficiency of 6.22% is one of the highest PCEs for NF all-SMSC-based PBI acceptors so far. The studies illustrate that highly efficient NF all-SMSCs can be achieved by using a PBI acceptor with a suitable SVA process.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology , Beijing 100029, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Xin
authors.affiliation: Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Jiajing
authors.initials: J
authors.lastname: Feng
authors.affiliation: Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Wei
authors.identifier: http://orcid.org/0000-0002-0153-7796
authors.initials: W
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology , Beijing 100029, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Meng
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology , Beijing 100029, China.
authors.forename: Zhongjie
authors.initials: Z
authors.lastname: Ren
authors.affiliation: Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology , Beijing 100029, China.
authors.forename: Shouke
authors.initials: S
authors.lastname: Yan
keywords: nonfullerene acceptor; nonfullerene all-small-molecule organic solar cells; perylene bisimide; solvent-vapor annealing; twisted conformation