Department of Physics, Zhejiang Normal University, Jinhua, Zhejiang, China.
J Phys Chem B. 2011 Feb 10;115(5):869-73. doi: 10.1021/jp109452n. Epub 2010 Dec 21.
Through combining the electron transition process and dipole moment evolution as well as electron-phonon coupling, molecular dynamics calculations show that the radiative decay of singlet excitons in a conjugated polymer, such as a polymer light-emitting diode (PLED), is largely determined by the evolution of the dipole moment. Without an electric field, the decay life of a singlet exciton is about 1 ns. Once an electric field is applied and exceeds a critical value, with electron-phonon coupling, the original lattice structure evolves into two new localized lattice distortions, consistent with the experimental results. Owing to the new lattice structure and self-trapping, the dipole moment rapidly decreases to zero within 5 fs, eliminating the radiative decay of the singlet exciton.
通过结合电子跃迁过程和偶极矩演化以及电子-声子耦合，分子动力学计算表明，共轭聚合物（如聚合物发光二极管（PLED））中单重激子的辐射衰减主要取决于偶极矩的演化。在没有电场的情况下，单重激子的衰减寿命约为 1 ns。一旦施加电场并超过临界值，通过电子-声子耦合，原始晶格结构演变成两个新的局域晶格畸变，与实验结果一致。由于新的晶格结构和自陷，偶极矩在 5 fs 内迅速降至零，从而消除了单重激子的辐射衰减。
