New Non-Fullerene Acceptor with Extended Conjugation of Cyclopenta [2,1-b:3,4-b’] Dithiophene for Organic Solar Cells
Cheng Sun,
Sanseong Lee,
Changeun Choi,
Soyeong Jeong,
Juhui Oh,
Ju-Hyeon Kim,
Jaeyoung Kim,
Ho Eon Baek,
Hongkyu Kang,
Soo-Young Jang,
Hyun Ho Choi,
Kwanghee Lee,
Yun-Hi Kim
Affiliations
Cheng Sun
Department of Chemistry and RIGET, Gyeongsang National University, Jinju 52828, Korea
Sanseong Lee
School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
Changeun Choi
Department of Materials Engineering and Convergence Technology and RIGET, Gyeongsang National University, Jinju 52828, Korea
Soyeong Jeong
Heeger Center for Advanced Materials, Research Institute for Solar and Sustainable Energies, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
Juhui Oh
School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
Ju-Hyeon Kim
School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
Jaeyoung Kim
School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
Ho Eon Baek
Department of Chemistry and RIGET, Gyeongsang National University, Jinju 52828, Korea
Hongkyu Kang
Center for Research Innovation, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
Soo-Young Jang
Research Institute for Solar and Sustainable Energies, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
Hyun Ho Choi
Department of Materials Engineering and Convergence Technology and RIGET, Gyeongsang National University, Jinju 52828, Korea
Kwanghee Lee
School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
Yun-Hi Kim
Department of Chemistry and RIGET, Gyeongsang National University, Jinju 52828, Korea
Herein, we design and characterize 9-heterocyclic ring non-fullerene acceptors (NFAs) with the extended backbone of indacenodithiophene by cyclopenta [2,1-b:3,4-b’] dithiophene (CPDT). The planar conjugated CPDT donor enhances absorption by reducing vibronic transition and charge transport. Developed NFAs with different end groups shows maximum absorption at approximately 790–850 nm in film. Because of the electronegative nature of the end-group, the corresponding acceptors showed deeper LUMO energy levels and red-shifted ultraviolet absorption. We investigate the crystallinity, film morphology, surface energy, and electronic as well as photovoltaic performance. The organic photovoltaic cells using novel NFAs with the halogen end groups fluorine or chlorine demonstrate better charge collection and faster exciton dissociation than photovoltaic cells using NFAs with methyl or lacking a substituent. Photovoltaic devices constructed from m-Me-ITIC with various end groups deliver power conversion efficiencies of 3.6–11.8%.
