Ductile Oligomeric Acceptor-Modified Flexible Organic Solar Cells Show Excellent Mechanical Robustness and Near 18% Efficiency

Qinrui Ye; Zhenyu Chen; Daobin Yang; Wei Song; Jintao Zhu; Shuncheng Yang; Jinfeng Ge; Fei Chen; Ziyi Ge

doi:10.1002/adma.202305562

Ductile Oligomeric Acceptor-Modified Flexible Organic Solar Cells Show Excellent Mechanical Robustness and Near 18% Efficiency

Adv Mater. 2023 Nov;35(44):e2305562. doi: 10.1002/adma.202305562. Epub 2023 Sep 21.

Authors

Qinrui Ye^{1

2}, Zhenyu Chen^{1

2}, Daobin Yang^{1

2}, Wei Song^{1

2}, Jintao Zhu³, Shuncheng Yang¹, Jinfeng Ge^{1

2}, Fei Chen³, Ziyi Ge^{1

2}

Affiliations

¹ Zhejiang Engineering Research Center for Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
³ Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo, 315100, China.

PMID: 37606278
DOI: 10.1002/adma.202305562

Abstract

High power conversion efficiency (PCE) and mechanical robustness are key requirements for wearable applications of organic solar cells (OSCs). However, almost all highly efficient photoactive films comprising polymer donors (P_D ) and small molecule acceptors (SMAs) are mechanically brittle. In this study, highly efficient (PCE = 17.91%) and mechanically robust (crack-onset strain [COS] = 11.7%) flexible OSCs are fabricated by incorporating a ductile oligomeric acceptor (DOA) into the P_D :SMA system, representing the most flexible OSCs to date. The photophysical, mechanical, and photovoltaic properties of D18:N3 with different DOAs are characterized. By introducing DOA DOY-C4 with a longer flexible alkyl linker and lower polymerization, the D18:N3:DOY-C4-based flexible OSCs exhibit a significantly higher PCE (17.91%) and 50% higher COS (11.7%) than the D18:N3-based device (PCE = 17.06%, COS = 7.8%). The flexible OSCs based on D18:N3:DOY-C4 retain 98% of the initial PCE after 2000 consecutive bending cycles, showing greater mechanical stability than the reference device (maintaining 89% of initial PCE). After careful investigation, it is hypothesized that the enhancement in mechanical properties is mainly due to the formation of tie chains or entanglement in the ternary blend films. These results demonstrate that DOAs have great potential for achieving high-performance flexible OSCs.

Keywords: crack-onset strain; flexible; mechanical robustness; oligomer acceptors; organic solar cells.

Abstract

Grants and funding