9.73% Efficiency Nonfullerene All Organic Small Molecule Solar Cells with Absorption-Complementary Donor and Acceptor

Haijun Bin; Yankang Yang; Zhi-Guo Zhang; Long Ye; Masoud Ghasemi; Shanshan Chen; Yindong Zhang; Chunfeng Zhang; Chenkai Sun; Lingwei Xue; Changduk Yang; Harald Ade; Yongfang Li

doi:10.1021/jacs.6b12826

9.73% Efficiency Nonfullerene All Organic Small Molecule Solar Cells with Absorption-Complementary Donor and Acceptor

J Am Chem Soc. 2017 Apr 12;139(14):5085-5094. doi: 10.1021/jacs.6b12826. Epub 2017 Mar 29.

Authors

Haijun Bin^{1

2}, Yankang Yang^{1

2}, Zhi-Guo Zhang¹, Long Ye³, Masoud Ghasemi³, Shanshan Chen⁴, Yindong Zhang^{5

6}, Chunfeng Zhang^{5

6}, Chenkai Sun^{1

2}, Lingwei Xue¹, Changduk Yang⁴, Harald Ade³, Yongfang Li^{1

2

7}

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
² School of Chemistry and Chemical Engineering, 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, North Carolina 27695, United States.
⁴ Department of Energy Engineering, School of Energy and Chemical Engineering, Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, South Korea.
⁵ National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China.
⁶ Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China.
⁷ Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou, Jiangsu 215123, China.

PMID: 28322045
DOI: 10.1021/jacs.6b12826

Abstract

In the last two years, polymer solar cells (PSCs) developed quickly with n-type organic semiconductor (n-OSs) as acceptor. In contrast, the research progress of nonfullerene organic solar cells (OSCs) with organic small molecule as donor and the n-OS as acceptor lags behind. Here, we synthesized a D-A structured medium bandgap organic small molecule H11 with bithienyl-benzodithiophene (BDTT) as central donor unit and fluorobenzotriazole as acceptor unit, and achieved a power conversion efficiency (PCE) of 9.73% for the all organic small molecules OSCs with H11 as donor and a low bandgap n-OS IDIC as acceptor. A control molecule H12 without thiophene conjugated side chains on the BDT unit was also synthesized for investigating the effect of the thiophene conjugated side chains on the photovoltaic performance of the p-type organic semiconductors (p-OSs). Compared with H12, the 2D-conjugated H11 with thiophene conjugated side chains shows intense absorption, low-lying HOMO energy level, higher hole mobility and ordered bimodal crystallite packing in the blend films. Moreover, a larger interaction parameter (χ) was observed in the H11 blends calculated from Hansen solubility parameters and differential scanning calorimetry measurements. These special features combined with the complementary absorption of H11 donor and IDIC acceptor resulted in the best PCE of 9.73% for nonfullerene all small molecule OSCs up to date. Our results indicate that fluorobenzotriazole based 2D conjugated p-OSs are promising medium bandgap donors in the nonfullerene OSCs.