High-Efficiency Organic Photovoltaics using Eutectic Acceptor Fibrils to Achieve Current Amplification

Ming Zhang; Lei Zhu; Tianyu Hao; Guanqing Zhou; Chaoqun Qiu; Zhe Zhao; Nicolai Hartmann; Biao Xiao; Yecheng Zou; Wei Feng; Haiming Zhu; Maojie Zhang; Yongming Zhang; Yongfang Li; Thomas P Russell; Feng Liu

doi:10.1002/adma.202007177

High-Efficiency Organic Photovoltaics using Eutectic Acceptor Fibrils to Achieve Current Amplification

Adv Mater. 2021 May;33(18):e2007177. doi: 10.1002/adma.202007177. Epub 2021 Mar 19.

Authors

Ming Zhang¹, Lei Zhu¹, Tianyu Hao¹, Guanqing Zhou¹, Chaoqun Qiu¹, Zhe Zhao¹, Nicolai Hartmann², Biao Xiao³, Yecheng Zou⁴, Wei Feng⁴, Haiming Zhu⁵, Maojie Zhang⁶, Yongming Zhang^{1

4}, Yongfang Li⁶, Thomas P Russell⁷, Feng Liu^{1

4}

Affiliations

¹ School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
² Neaspec GmbH, Eglfinger Weg 2, Haar, 85540, Germany.
³ Key Laboratory of Optoelectronic Chemical Materials and Devices, Ministry of Education, School of Chemical and Environmental Engineering, Jianghan University, Hubei, 430056, P. R. China.
⁴ State Key Laboratory of Fluorinated Functional Membrane Materials and Dongyue Future Hydrogen Energy Materials Company, Zibo City, Shandong, 256401, P. R. China.
⁵ Department of Chemistry, Zhejiang University, Zhejiang, 310027, P. R. China.
⁶ Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu, 215123, P. R. China.
⁷ Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA, 01003, USA.

PMID: 33742493
DOI: 10.1002/adma.202007177

Abstract

The intrinsic electronic properties of donor (D) and acceptor (A) materials in coupling with morphological features dictate the output in organic solar cells (OSCs). New physical properties of intimate eutectic mixing are used in nonfullerene-acceptor-based D-A₁ -A₂ ternary blends to fine-tune the bulk heterojunction thin film morphology as well as their electronic properties. With enhanced thin film crystallinity and improved carrier transport, a significant J_SC amplification is achieved due to the formation of eutectic fibrillar lamellae and reduced defects state density. Material wise, aligned cascading energy levels with much larger driving force, and suppressed recombination channels confirm efficient charge transfer and transport, enabling an improved power conversion efficiency (PCE) of 17.84%. These results reveal the importance of utilizing specific material interactions to control the crystalline habit in blended films to form a well-suited morphology in guiding superior performances, which is of high demand in the next episode of OSC fabrication toward 20% PCE.

Keywords: eutectic mixtures; nonfullerene acceptors; organic photovoltaics.