High-Efficiency All-Small-Molecule Organic Solar Cells Based on an Organic Molecule Donor with Alkylsilyl-Thienyl Conjugated Side Chains

Haijun Bin; Jia Yao; Yankang Yang; Indunil Angunawela; Chenkai Sun; Liang Gao; Long Ye; Beibei Qiu; Lingwei Xue; Chenhui Zhu; Chunhe Yang; Zhi-Guo Zhang; Harald Ade; Yongfang Li

doi:10.1002/adma.201706361

High-Efficiency All-Small-Molecule Organic Solar Cells Based on an Organic Molecule Donor with Alkylsilyl-Thienyl Conjugated Side Chains

Adv Mater. 2018 Jul;30(27):e1706361. doi: 10.1002/adma.201706361. Epub 2018 May 21.

Authors

Haijun Bin^{1

2}, Jia Yao^{1

3}, Yankang Yang^{1

2}, Indunil Angunawela⁴, Chenkai Sun¹, Liang Gao¹, Long Ye⁴, Beibei Qiu¹, Lingwei Xue¹, Chenhui Zhu⁵, Chunhe Yang³, Zhi-Guo Zhang¹, Harald Ade⁴, Yongfang Li^{1

2

6}

Affiliations

¹ CAS Research/Education Center for Excellence in 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 Chemistry, School of Science, Beijing JiaoTong University, Beijing, 100044, China.
⁴ Department of Physics and Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, 27695, USA.
⁵ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
⁶ Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123, China.

PMID: 29782668
DOI: 10.1002/adma.201706361

Abstract

Two medium-bandgap p-type organic small molecules H21 and H22 with an alkylsily-thienyl conjugated side chain on benzo[1,2-b:4,5-b']dithiophene central units are synthesized and used as donors in all-small-molecule organic solar cells (SM-OSCs) with a narrow-bandgap n-type small molecule 2,2'-((2Z,2'Z)-((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (IDIC) as the acceptor. In comparison to H21 with 3-ethyl rhodanine as the terminal group, H22 with cyanoacetic acid esters as the terminal group shows blueshifted absorption, higher charge-carrier mobility and better 3D charge pathway in blend films. The power conversion efficiency (PCE) of the SM-OSCs based on H22:IDIC reaches 10.29% with a higher open-circuit voltage of 0.942 V and a higher fill factor of 71.15%. The PCE of 10.29% is among the top efficiencies of nonfullerene SM-OSCs reported in the literature to date.

Keywords: alkylsilyl-thienyl conjugated side-chains; organic small-molecule donor materials; organic solar cells.