XU Lingxia; LIANG Yongqi

doi:10.7498/aps.74.20250798

Abstract

The high exciton binding energy of organic semiconductor materials limits charge separation efficiency. Investigating the excited state characteristics and modulation mechanisms of polymer donor and non-fullerene acceptor molecules is crucial for optimizing material design and enhancing the performance of organic photovoltaic devices. Therefore, this study investigates the excited state characteristics in polymer and non-fullerene organic materials. The tight-binding quantum mechanical method is used to systematically compare the excited state characteristics (including lattice geometry, band structure, and binding energy) between polymer donor and non-fullerene acceptor molecules, with particular emphasis on the role of electron-phonon coupling in modulating these excited state characteristics. The results indicate that non-fullerene acceptor molecules exhibit smaller lattice distortion, narrower bandgap, and lower binding energy than polymer donor molecules. It is precisely due to the different excited state characteristics of the polymer donor and non-fullerene acceptor molecules that the exciton binding energy in the organic photovoltaic system they constitute can be effectively reduced, while also providing a favorable energy-level shift for exciton dissociation. This significantly enhances the efficiency of charge transfer and separation. Furthermore, the decrease of electron-lattice coupling strength can further reduce these parameters in both polymer donor and non-fullerene acceptor molecules. By enhancing the electron-donating capability of central groups or the electron-withdrawing capacity of end groups in non-fullerene acceptor molecules, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels can be shifted upward or downward. The upshifted HOMO and LUMO energy levels are accompanied by an increase in molecular polarizability and a decrease in reorganization energy, while the downshifted HOMO and LUMO energy levels lead to an enhanced molecular dipole moment and improved electron affinity. This optimized energy-level structure further reduces the binding energy and achieves efficient charge separation. These findings demonstrate that the efficient charge transfer and separation in polymer/non-fullerene organic photovoltaic systems originate from their distinct molecular excited state characteristics. This basic understanding enables the rational design of high-performance organic optoelectronic materials and the development of novel organic photovoltaic devices by strategically adjusting the electron-phonon coupling strength and push-pull electronic structures of non-fullerene acceptors.

Keywords:

Authors and contacts

Corresponding author: XU Lingxia, xulx@sxdtdx.edu.cn

Funds: Project supported by the Fundamental Research Program of Shanxi Province, China (Grant No. 202303021222210), the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province, China (Grant No. 2023L261), and the Youth Science Foundation Program of Shanxi Datong University, China (Grant No. 2022Q39).

FullText HTML

References

[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]

Cited By

DownLoad: Full-Size Img PowerPoint

DownLoad: Full-Size Img PowerPoint

DownLoad: Full-Size Img PowerPoint

DownLoad: Full-Size Img PowerPoint

DownLoad: Full-Size Img PowerPoint

DownLoad: Full-Size Img PowerPoint

DownLoad: Full-Size Img PowerPoint

DownLoad: Full-Size Img PowerPoint

map

[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]

[1]	Jia Yun-Zhe, Meng Sheng. Ultrafast dynamics of water system under photoexcitation. Acta Physica Sinica, 2024, 73(8): 084204. doi: 10.7498/aps.73.20240047
[2]	Li Duo-Duo, Zhang Song. Molecular structures in the non-adiabatic relaxaiton processes of excited states of pentafluoropyridine. Acta Physica Sinica, 2024, 73(4): 043101. doi: 10.7498/aps.73.20231570
[3]	Xing Feng-Zhu, Cui Jian-Po, Wang Yan-Zhao, Gu Jian-Zhong. Two-proton emission from excited states of proton-rich nuclei. Acta Physica Sinica, 2022, 71(6): 062301. doi: 10.7498/aps.71.20211839
[4]	Zhang Jin-Fang, Ren Ya-Na, Wang Jun-Min, Yang Bao-Dong. Investigation of the two-color polarization spectroscopy between the excited states based on cesium atoms. Acta Physica Sinica, 2019, 68(11): 113201. doi: 10.7498/aps.68.20181872
[5]	Wang Wen-Jing, Li Chong, Zhang Mao-Mao, Gao Kun. Dynamical study of ultrafast exciton migration in coujugated polymers driven by nonuniform field. Acta Physica Sinica, 2019, 68(17): 177201. doi: 10.7498/aps.68.20190432
[6]	Yan Da-Dong, Zhang Xing-Hua. Recent development on the theory of polymer crystallization. Acta Physica Sinica, 2016, 65(18): 188201. doi: 10.7498/aps.65.188201
[7]	Liu Jun-Juan, Wei Zeng-Jiang, Chang Hong, Zhang Ya-Lin, Di Bing. Dynamics of polarons in organic conjugated polymers with impurity ions. Acta Physica Sinica, 2016, 65(6): 067202. doi: 10.7498/aps.65.067202
[8]	Zhao Cui-Lan, Wang Li-Li, Zhao Li-Li. Properties of excited state of polaron in quantum disk in finite depth parabolic potential well. Acta Physica Sinica, 2015, 64(18): 186301. doi: 10.7498/aps.64.186301
[9]	Huang Yong-Xian, Leng Jin-Song, Tian Xiu-Bo, Lü Shi-Xiong, Li Yao. The study on adaptability and effect of mesh-inducing for plasma immersion ion implantation on non-conductor polymer. Acta Physica Sinica, 2012, 61(15): 155206. doi: 10.7498/aps.61.155206
[10]	Gao Bo-Wen, Gao Chao, Que Wen-Xiu, Wei Wei. Recent development of polymer/fullerene photovoltaic cells. Acta Physica Sinica, 2012, 61(19): 194213. doi: 10.7498/aps.61.194213
[11]	Gao Shuang-Hong, Ren Zhao-Yu, Guo Ping, Zheng Ji-Ming, Du Gong-He, Wan Li-Juan, Zheng Lin-Lin. Magnetic properties and excited states of thegraphene quantum dots. Acta Physica Sinica, 2011, 60(4): 047105. doi: 10.7498/aps.60.047105
[12]	Xu Guo-Liang, Xia Yao-Zheng, Liu Xue-Feng, Zhang Xian-Zhou, Liu Yu-Fang. Effect of external electric field excitation on titanium monoxide. Acta Physica Sinica, 2010, 59(11): 7762-7768. doi: 10.7498/aps.59.7762
[13]	Xu Guo-Liang, Lü Wen-Jing, Liu Yu-Fang, Zhu Zun-Lüe, Zhang Xian-Zhou, Sun Jin-Feng. Effect of external electric field on the optical excitation of silicon dioxide. Acta Physica Sinica, 2009, 58(5): 3058-3063. doi: 10.7498/aps.58.3058
[14]	Shi Jing, Gao Kun, Lei Jie, Xie Shi-Jie. A real space study on the conducting polymer with a ground-state nondegenerate structure. Acta Physica Sinica, 2009, 58(1): 459-464. doi: 10.7498/aps.58.459
[15]	Zhang Ya-Ni. High birefringence tunable effect of microstructured polymer optical fiber. Acta Physica Sinica, 2008, 57(9): 5729-5734. doi: 10.7498/aps.57.5729
[16]	Xu Guo-Liang, Xiao Xiao-Hong, Geng Zhen-Duo, Liu Yu-Fang, Zhu Zheng-He. Effect of external electric field excitation on methyl vinyl siloxane. Acta Physica Sinica, 2007, 56(9): 5196-5201. doi: 10.7498/aps.56.5196
[17]	Wang Yi-Ping, Chen Jian-Ping, Li Xin-Wan, Zhou Jun-He, Shen Hao, Shi Chang-Hai, Zhang Xiao-Hong, Hong Jian-Xun, Ye Ai-Lun. Fast tunable electro-optic polymer waveguide gratings. Acta Physica Sinica, 2005, 54(10): 4782-4788. doi: 10.7498/aps.54.4782
[18]	Xu Guo-Liang, Zhu Zheng-He, Ma Mei-Zhong, Xie An-Dong. Study on the effect of external electric field excitation on methane. Acta Physica Sinica, 2005, 54(7): 3087-3093. doi: 10.7498/aps.54.3087
[19]	Cao Wan-Qiang, Li Jing-De. . Acta Physica Sinica, 2002, 51(7): 1634-1638. doi: 10.7498/aps.51.1634
[20]	HOU CHUN-FENG, ABDURUSUL, DU CHUN-GUANG, SUN XIU-DONG, LI SHI-QUN. SPATIAL SOLITONS IN PHOTOREFRACTIVE ORGANIC POLYMERS. Acta Physica Sinica, 2001, 50(11): 2159-2165. doi: 10.7498/aps.50.2159

Catalog

Vol. 74, Issue 20 - 2025-10-20

Metrics

Abstract views: 902
PDF Downloads: 25
Cited By: 0

姓名
邮箱
手机号码
标题
留言内容
验证码

Search

Article

留言板

Abstract

Authors and contacts

Corresponding author: XU Lingxia, xulx@sxdtdx.edu.cn

FullText HTML

References

Cited By

Catalog

Metrics

Authors

Referees

About Journal

About

Search

Article

留言板

Abstract

Authors and contacts

Corresponding author: XU Lingxia, xulx@sxdtdx.edu.cn

FullText HTML

References

Cited By

Catalog

Metrics

Publishing process

Authors

Referees

About Journal

About