Introducing a Phenyl End Group in the Inner Side Chains of A-DA'D-A Acceptors Enables High-Efficiency Organic Solar Cells Processed with Nonhalogenated Solvent

Xiangxi Wu; Xin Jiang; Xiaojun Li; Jinyuan Zhang; Kan Ding; Hongmei Zhuo; Jing Guo; Jing Li; Lei Meng; Harald Ade; Yongfang Li

doi:10.1002/adma.202302946

Introducing a Phenyl End Group in the Inner Side Chains of A-DA'D-A Acceptors Enables High-Efficiency Organic Solar Cells Processed with Nonhalogenated Solvent

Adv Mater. 2023 Nov;35(48):e2302946. doi: 10.1002/adma.202302946. Epub 2023 Oct 27.

Authors

Xiangxi Wu^{1

2}, Xin Jiang^{1

2}, Xiaojun Li^{1

2}, Jinyuan Zhang¹, Kan Ding³, Hongmei Zhuo^{1

2}, Jing Guo², Jing Li⁴, Lei Meng^{1

2}, Harald Ade³, Yongfang Li^{1

2

5}

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
² School of Chemical Science, University of Chinese Academy of Sciences, Beijing, 100049, China.
³ Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, 27695, USA.
⁴ Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
⁵ Laboratory of Advanced Optoelectronic Materials, Suzhou Key Laboratory of Novel Semiconductor Materials and Devices, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123, China.

PMID: 37515820
DOI: 10.1002/adma.202302946

Abstract

Power conversion efficiency (PCE) of organic solar cells (OSCs) processed by nonhalogenated solvents is unsatisfactory due to the unfavorable morphology. Herein, two new small molecule acceptors (SMAs) Y6-Ph and L8-Ph are synthesized by introducing a phenyl end group in the inner side chains of the SMAs of Y6 and L8-BO, respectively, for overcoming the excessive aggregation of SMAs in the long-time film forming processed by nonhalogenated solvents. First, the effect of the film forming time on the aggregation property and photovoltaic performance of Y6, L8-BO, Y6-Ph, and L8-Ph is studied by using the commonly used solvents: chloroform (CF) (rapid film forming process) and chlorobenzene (CB) (slow film forming process). It is found that Y6- and L8-BO-based OSCs exhibit a dramatic drop in PCE from CF- to CB-processed devices owing to the large phase separation, while the Y6-Ph and L8-Ph based OSCs show obviously increased PCEs Furthermore, L8-Ph-based OSCs processed by nonhalogenated solvent o-xylene (o-XY) achieved a high PCE of 18.40% with an FF of 80.11%. The results indicate that introducing a phenyl end group in the inner side chains is an effective strategy to modulate the morphology and improve the photovoltaic performance of the OSCs processed by nonhalogenated solvents.

Keywords: A-DA'D-A type small molecule acceptors; morphology regulation; nonhalogenated solvent; organic solar cells; phenyl end group of inner side chains.

Abstract

Grants and funding