Tonami Takayoshi, Nagami Takanori, Okada Kenji, Yoshida Wataru, Nakano Masayoshi
Department of Materials Engineering Science, Graduate School of Engineering Science, Center for Spintronics Research Network (CSRN), Graduate School of Engineering Science, and Quantum Information and Quantum Biology Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Toyonaka, Osaka 560-8531, Japan.
Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan.
ACS Omega. 2019 Sep 20;4(14):16181-16190. doi: 10.1021/acsomega.9b02378. eCollection 2019 Oct 1.
Using quantum chemical calculations and exciton dynamics simulations, we investigate the static second hyperpolarizability γ [the third-order nonlinear optical (NLO) property at the molecular scale] of slip-stacked pentacene dimer models in the correlated-triplet-pair [(TT)] state created from the singlet excited state in the singlet fission (SF) process. It is found that the SF induces significant (∼20 times at maximum) enhancement of γ/monomer in the (TT) state as compared to that in the singlet ground state. The origin of the remarkable enhancement of γ/monomer is revealed by analyzing the γ density distribution and the intermolecular orbital interaction. Furthermore, we clarify molecular packings suitable for highly efficient SF and largely enhanced γ values of a novel class of SF-induced NLO systems, which have promising potential to surpass the conventional NLO systems.
利用量子化学计算和激子动力学模拟，我们研究了在单重态裂变（SF）过程中由单重态激发态产生的关联三重态对[（TT）]态下，滑移堆积并五苯二聚体模型的静态二阶超极化率γ（分子尺度上的三阶非线性光学（NLO）性质）。研究发现，与单重态基态相比，SF使（TT）态下的γ/单体显著增强（最大约20倍）。通过分析γ密度分布和分子间轨道相互作用，揭示了γ/单体显著增强的起源。此外，我们阐明了适用于高效SF且能大幅提高一类新型SF诱导NLO系统γ值的分子堆积方式，这类系统具有超越传统NLO系统的潜力。
