面向有机光电材料的电子激发态结构与过程的计算方法

Computational methodologies for the electronic excited states structure and processes for organic optoelectronic materials

共轭聚合物与有机分子材料中的电子激发结构与过程决定了材料的光电功能:根据Kasha规则,低能级激发态的排序决定能否发光;最低激发态至基态的辐射跃迁与无辐射跃迁之间的竞争决定了发光效率,后者主要由非绝热耦合(声子作用)决定;电荷激发态载体的传输由电子分布与振动耦合或杂质和无序的散射弛豫过程决定.本文针对有机功能材料的发光性能,介绍两种理论方法的研究进展,即可用于计算共轭聚合物激发态结构的量子化学密度矩阵重整化群方法和计算发光效率的多模耦合无辐射跃迁速率方法.这些方法被应用于有机功能材料的性能预测和分子设计中.

The electronic excited states structure and their processes determine the optoelectronic properties for conjugated organic molecules and polymers： According to Kasha＇s rule, the ordering of the lowest-lying excited states determines whether a molecule or material can emit light or not; the luminescence quantum efficiency stems from the competition between the radiative and the non-radiative transition determines the light-emitting efficiency, the latter being dictated by non-adiabatic coupling （electron-phonon interaction）; charge carrier transport is determined by the scattering/relaxation of electron distribution function with vibrations or impurities or disorders. In this review, we summarized the advances in theoretical methodology development towards quantitative prediction of the optoelectronic properties for organic materials, including the quantum chemistry density matrix renormalization group theory for the excited state structure in conjugated chains, and the multi-mode mixing non-radiative decay formalism for light-emitting efficiency. The methods have been applied to the prediction of optoelectronic properties of organic functional materials and molecular design.