Correlating Charge Transfer Dynamics with Interfacial Trap States in High-Efficiency Organic Solar Cells

Wang, Tong1; Chen, Zhi-Hao1; Qiao, Jia-Wei1; Qin, Wei1; Liu, Jian-Qiang1; Wang, Xing-Zhu2; Pu, Yong-Jin3; Yin, Hang1; Hao, Xiao-Tao1,4

2023-02-01

10.1021/acsami.2c21470

ACS Applied Materials & Interfaces   Impact Factor & Quartile

1944-8244

1944-8252

The charge transfer between the donor and acceptor determines the photogenerated carrier density in organic solar cells. However, a fundamental understanding regarding the charge transfer at donor/acceptor interfaces with high-density traps has not been fully addressed. Herein, a general correlation between trap densities and charge transfer dynamics is established by adopting a series of high-efficiency organic photovoltaic blends. It is found that the electron transfer rates are reduced with increased trap densities, while the hole transfer rates are independent of trap states. The local charges captured by traps can induce potential barrier formation around recombination centers, leading to the suppression of electron transfer. For the hole transfer process, the thermal energy provides a sufficient driving force, which ensures an efficient transfer rate. As a result, a 17.18% efficiency is obtained for PM6:BTP-eC9-based devices with the lowest interfacial trap densities. This work highlights the importance of interfacial traps in charge transfer processes and proposes an underlying insight into the charge transfer mechanism at nonideal interfaces in organic heterostructures.

organic solar cells interfacial trap states potential barrier charge transfer rates thermal activation

SCI

English

Others

Major Program of Natural Science Foundation of Shandong Province[ZR2019ZD43] ; Natural Science Foundation of China[52073162] ; ARC Centre of Excellence in Exciton Science[CE170100026] ; National Key R&D program for International Collaboration[2021YFE0191500] ; Shenzhen Science and Technology Innovation Committee[JCYJ 20190809150213448]

Science & Technology - Other Topics ; Materials Science

Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary

WOS:000936880500001

AMER CHEMICAL SOC

Web of Science

1.Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Peoples R China
2.Southern Univ Sci & Technol, Acad Adv Interdisciplinary Studies, Shenzhen 518055, Guangdong Provi, Peoples R China
3.RIKEN Ctr Emergent Matter Sci CEMS, 2-1 Hirosawa, Wako, Saitama 3510198, Japan
4.Univ Melbourne, ARC Ctr Excellence Exciton Sci, Sch Chem, Parkville, Vic 3010, Australia

Wang, Tong,Chen, Zhi-Hao,Qiao, Jia-Wei,et al. Correlating Charge Transfer Dynamics with Interfacial Trap States in High-Efficiency Organic Solar Cells[J]. ACS Applied Materials & Interfaces,2023.

Wang, Tong.,Chen, Zhi-Hao.,Qiao, Jia-Wei.,Qin, Wei.,Liu, Jian-Qiang.,...&Hao, Xiao-Tao.(2023).Correlating Charge Transfer Dynamics with Interfacial Trap States in High-Efficiency Organic Solar Cells.ACS Applied Materials & Interfaces.

Wang, Tong,et al."Correlating Charge Transfer Dynamics with Interfacial Trap States in High-Efficiency Organic Solar Cells".ACS Applied Materials & Interfaces (2023).