Fe Single Atom Catalysts Promoting Polysulfide Redox Reduction in Quantum Dot Photovoltaics

Linna Li; Yu Lin; Yongming Xia; Di Lin; Xiang Yang; Jiaqi Fang; Xuehui Liu; Jiawen Chen; Xiong Yin; Chenyan Ma; Xiaoying Yan; Peng Xu; Rui Xu; Lipeng Zhang; Zhihai Cheng; Leyu Wang

doi:10.1021/acs.nanolett.3c01064

Fe Single Atom Catalysts Promoting Polysulfide Redox Reduction in Quantum Dot Photovoltaics

Nano Lett. 2023 Jun 14;23(11):5123-5130. doi: 10.1021/acs.nanolett.3c01064. Epub 2023 Jun 5.

Authors

Linna Li¹, Yu Lin², Yongming Xia¹, Di Lin¹, Xiang Yang¹, Jiaqi Fang¹, Xuehui Liu¹, Jiawen Chen¹, Xiong Yin¹, Chenyan Ma³, Xiaoying Yan⁴, Peng Xu⁴, Rui Xu⁵, Lipeng Zhang¹, Zhihai Cheng⁵, Leyu Wang¹

Affiliations

¹ State Key Laboratory of Chemical Resource Engineering, State Key Laboratory of Organic-Inorganic Composites, Innovation Centre for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
² College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
³ Beijing Synchrotron Radiation Facility (BSRF), Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
⁴ CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
⁵ Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Department of Physics, Renmin University of China, Beijing 100872, China.

PMID: 37272668
DOI: 10.1021/acs.nanolett.3c01064

Abstract

Developing cost-effective and highly efficient photocathodes toward polysulfide redox reduction is highly desirable for advanced quantum dot (QD) photovoltaics. Herein, we demonstrate nitrogen doped carbon (N-C) shell-supported iron single atom catalysts (Fe-SACs) capable of catalyzing polysulfide reduction in QD photovoltaics for the first time. Specifically, Fe-SACs with FeN₄ active sites feature a power conversion efficiency of 13.7% for ZnCuInSe-QD photovoltaics (AM1.5G, 100 mW/cm²), which is the highest value for ZnCuInSe QD-based photovoltaics, outperforming those of Cu-SACs and N-C catalysts. Compared with N-C, Fe-SACs exhibit suitable energy level matching with polysulfide redox couples, revealed by the Kelvin probe force microscope, which accelerates the charge transferring at the interfaces of catalyst/polysulfide redox couple. Density functional theory calculations demonstrate that the outstanding catalytic activity of Fe-SACs originates from the preferable adsorption of S₄^2- on the FeN₄ active sites and the high activation degree of the S-S bonds in S₄^2- initiated by the FeN₄ active sites.

Keywords: Kelvin probe force microscope; Polysulfide redox reduction; charge transfer; hard template method; single-atom catalysts; solar cells.