Chen Yichuan, Cheng Yuqing, Sun Mengtao
School of Mathematics and Physics, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Nanoscale. 2022 May 19;14(19):7269-7279. doi: 10.1039/d1nr08163b.
The nonlinear optical properties of a D-A (donor-acceptor) conjugated organic molecule with polythiophene (PT) as the donor and indene-C bisadduct (ICBA) as the acceptor are theoretically investigated, which exhibits a large two-photon absorption (TPA) cross-section up to 8000 GM at the wavelength of 780 nm. Combining surface plasmon resonances (SPRs) with nonlinear optics, nonlinear properties can be strongly enhanced. In this paper, an appropriate nonlinear plexciton method by the coupling of Au@Ag nanorods and an Ag film is designed, in which the TPA properties of the PT:ICBA complex can be increased by 10 times. The angle dependence on polarization and incidence is investigated to obtain the maximum of plasmonic enhancement. Our results emphasize the physical mechanism of nonlinear plexcitons and provide a feasible method to improve the nonlinear properties of organic solar cell materials.
理论上研究了一种以聚噻吩（PT）为供体、茚-C双加合物（ICBA）为受体的D-A（供体-受体）共轭有机分子的非线性光学性质，该分子在780 nm波长处表现出高达8000 GM的大二阶非线性吸收（TPA）截面。将表面等离子体共振（SPR）与非线性光学相结合，可以显著增强非线性特性。本文设计了一种通过金@银纳米棒与银膜耦合的合适的非线性激子方法，其中PT:ICBA复合物的TPA特性可提高10倍。研究了偏振和入射角的依赖性，以获得等离子体增强的最大值。我们的结果强调了非线性激子的物理机制，并提供了一种改善有机太阳能电池材料非线性特性的可行方法。
