title: Efficient Polymer Solar Cells with High Open-Circuit Voltage Containing Diketopyrrolopyrrole-Based Non-Fullerene Acceptor Core End-Capped with Rhodanine Units.
abstract: Herein we report the synthesis of a novel A-D-A-D-A non-fullerene small-molecule acceptor (NFSMA) bearing a diketopyrrolopyrrole (DPP) acceptor central core coupled to terminal rhodanine acceptors via a thiophene donor linker (denoted as MPU1) for use in non-fullerene polymer solar cells (PSCs). This NFSMA exhibits a narrow optical band gap (1.48 eV), strong absorption in the 600-800 nm wavelength region of the solar spectrum, and a lowest unoccupied energy level of -3.99 eV. When the mixture of a medium band gap D-A copolymer P (1.75 eV) was used as donor and MPU1 as acceptor, the blend film showed a broad absorption profile from 400 to 850 nm, beneficial for light harvesting efficiency of the resulted polymer solar cell. After optimization of the donor-to-acceptor weight ratios and concentration of solvent additive, the P-MPU1-based PSC exhibited a power conversion efficiency of 7.52% (Jsc= 12.37 mA/cm2, Voc= 0.98 V, and fill factor = 0.62), which is much higher than that for a P3HT-MPU1-based device (2.16%) prepared under identical conditions. The higher value for the P-MPU1-based device relative to the P3HT-MPU1-based one is related to the low energy loss and more balanced charge transport in the device based on the P donor. These results indicate that alteration of the absorption spectra and electrochemical energy levels of non-fullerene acceptors, and appropriate selection of the polymer donor with complementary absorption profile, is a promising means to further boost the performance of PSCs.
authors.affiliation: Institute of Nanoscience, Nanotechnology and Molecular Materials, Universidad de Castilla-La Mancha , Campus de la Fábrica de Armas, 45071 Toledo, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Privado
authors.affiliation: Institute of Nanoscience, Nanotechnology and Molecular Materials, Universidad de Castilla-La Mancha , Campus de la Fábrica de Armas, 45071 Toledo, Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: Cuesta
authors.affiliation: Institute of Nanoscience, Nanotechnology and Molecular Materials, Universidad de Castilla-La Mancha , Campus de la Fábrica de Armas, 45071 Toledo, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: de la Cruz
authors.affiliation: A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilova Street, Moscow 119991, Russia.
authors.forename: Mukhamed L
authors.initials: ML
authors.lastname: Keshtov
authors.affiliation: Department of Physics, Malaviya National Institute of Technology , Jaipur 302017, Rajasthan, India.
authors.forename: Rahul
authors.initials: R
authors.lastname: Singhal
authors.affiliation: Department of Physics, Malaviya National Institute of Technology , Jaipur 302017, Rajasthan, India.|Department of Physics, LNM Institute of Information Technology , Rupa ki Nagal, Jamdoli, Jaipur 302031, Rajasthan, India.
authors.forename: Ganesh D
authors.initials: GD
authors.lastname: Sharmad
authors.affiliation: Institute of Nanoscience, Nanotechnology and Molecular Materials, Universidad de Castilla-La Mancha , Campus de la Fábrica de Armas, 45071 Toledo, Spain.
authors.forename: Fernando
authors.identifier: http://orcid.org/0000-0002-7694-7722
authors.initials: F
authors.lastname: Langa
keywords: BHJ; diketopyrrolopyrrole; non-fullerene acceptor; organic solar cells; rhodanine