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Understanding the correlation between energy-state mismatching and open-circuit voltage loss in bulk heterojunction solar cells

  • Hyun-Seock Yang 1,2 ,
  • Danbi Kim 1,3 ,
  • Chang-Mok Oh 4 ,
  • Vellaiappillai Tamilavan 1,3 ,
  • Pesi M. Hangoma 1,3 ,
  • Hojun Yi 1,3 ,
  • Bo R. Lee 1,3 ,
  • Insoo Shin , 5 ,
  • In-Wook Hwang , 4 ,
  • Sung Heum Park , 1,3
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  • 1. Pukyong National University, Busan, Republic of Korea
  • 2. Clarendon Laboratory, University of Oxford, Oxford, UK
  • 3. Institute of Energy Transport and Fusion Research, Pukyong National University, Busan, Republic of Korea
  • 4. Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
  • 5. Department of Chemical and Biomolecular Engineering, Tandon School of Engineering, New York University, Brooklyn, New York, USA
is2708@nyu.edu
hwangiw@gist.ac.kr
spark@pknu.ac.kr

Received date: 09 May 2023

Revised date: 19 Jun 2023

Accepted date: 28 Jun 2023

Copyright

2024 2024 The Authors. Carbon Energy published by Wenzhou University and John Wiley & Sons Australia, Ltd.

Abstract

Photoinduced intermolecular charge transfer (PICT) determines the voltage loss in bulk heterojunction (BHJ) organic photovoltaics (OPVs), and this voltage loss can be minimized by inducing efficient PICT, which requires energy-state matching between the donor and acceptor at the BHJ interfaces. Thus, both geometrically and energetically accessible delocalized state matching at the hot energy level is crucial for achieving efficient PICT. In this study, an effective method for quantifying the hot state matching of OPVs was developed. The degree of energy-state matching between the electron donor and acceptor at BHJ interfaces was quantified using a mismatching factor (MF) calculated from the modified optical density of the BHJ. Furthermore, the correlation between the open-circuit voltage (Voc) of the OPV device and energy-state matching at the BHJ interface was investigated using the calculated MF. The OPVs with small absolute MF values exhibited high Voc values. This result clearly indicates that the energy-state matching between the donor and acceptor is crucial for achieving a high Voc in OPVs. Because the MF indicates the degree of energy-state matching, which is a critical factor for suppressing energy loss, it can be used to estimate the Voc loss in OPVs.

Cite this article

Hyun-Seock Yang, Danbi Kim, Chang-Mok Oh, Vellaiappillai Tamilavan, Pesi M. Hangoma, Hojun Yi, Bo R. Lee, Insoo Shin, In-Wook Hwang, Sung Heum Park. Understanding the correlation between energy-state mismatching and open-circuit voltage loss in bulk heterojunction solar cells[J]. Carbon Energy, 2024, 6(5): 433. DOI: 10.1002/cey2.433

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