Nanographene-Osmapentalyne Complexes as a Cathode Interlayer in Organic Solar Cells Enhance Efficiency over 18

Longzhu Liu; Shiyan Chen; Yangyang Qu; Xiang Gao; Liang Han; Zhiwei Lin; Liulin Yang; Wei Wang; Nan Zheng; Yongye Liang; Yuanzhi Tan; Haiping Xia; Feng He

doi:10.1002/adma.202101279

Nanographene-Osmapentalyne Complexes as a Cathode Interlayer in Organic Solar Cells Enhance Efficiency over 18

Adv Mater. 2021 Jul;33(30):e2101279. doi: 10.1002/adma.202101279. Epub 2021 Jun 12.

Authors

Longzhu Liu¹, Shiyan Chen², Yangyang Qu², Xiang Gao², Liang Han³, Zhiwei Lin², Liulin Yang², Wei Wang⁴, Nan Zheng⁵, Yongye Liang⁴, Yuanzhi Tan², Haiping Xia^{1

2

3}, Feng He^{1

3}

Affiliations

¹ Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China.
² State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
³ Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, 518055, China.
⁴ Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
⁵ Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China.

PMID: 34117664
DOI: 10.1002/adma.202101279

Abstract

Interface engineering is a critical method by which to efficiently enhance the photovoltaic performance of nonfullerene solar cells (NFSC). Herein, a series of metal-nanographene-containing large transition metal involving d_π -p_π conjugated systems by way of the addition reactions of osmapentalynes and p-diethynyl-hexabenzocoronenes is reported. Conjugated extensions are engineered to optimize the π-conjugation of these metal-nanographene molecules, which serve as alcohol-soluble cathode interlayer (CIL) materials. Upon extension of the π-conjugation, the power conversion efficiency (PCE) of PM6:BTP-eC9-based NFSCs increases from 16% to over 18%, giving the highest recorded PCE. It is deduced by X-ray crystallographic analysis, interfacial contact methods, morphology characterization, and carrier dynamics that modification of hexabenzocoronenes-styryl can effectively improve the short-circuit current density (J_sc ) and fill factor of organic solar cells (OSCs), mainly due to the strong and ordered charge transfer, more matching energy level alignments, better interfacial contacts between the active layer and the electrodes, and regulated morphology. Consequently, the carrier transport is largely facilitated, and the carrier recombination is simultaneously impeded. These new CIL materials are broadly able to enhance the photovoltaic properties of OSCs in other systems, which provides a promising potential to serve as CILs for higher-quality OSCs.

Keywords: cathode interlayers; d π-p π conjugation; hexabenzocoronene; organic solar cells; osmapentalyne.

Abstract

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