Using an innovative quantum mechanical method for an open quantum system, we observe in real time and space the generation, migration, and dissociation of electron-hole pairs, transport of electrons and holes, and current emergence in an organic photovoltaic cell. Ehrenfest dynamics is used to study photoexcitation of thiophene:fullerene stacks coupled with a time-dependent density functional tight-binding method. Our results display the generation of an electron-hole pair in the donor and its subsequent migration to the donor-acceptor interface. At the interface, electrons transfer from the lowest unoccupied molecular orbitals (LUMOs) of thiophenes to the second LUMOs of fullerene. Further migration of electrons and holes leads to the emergence of current. These findings support previous experimental evidence of coherent couplings between electronic and vibrational degrees of freedom and are expected to stimulate further work toward exploring the interplay between electron-hole pair (exciton) binding and vibronic coupling for charge separation and transport.

使用开放量子系统的创新量子力学方法，我们实时和空间地观察有机光伏电池中电子-空穴对的产生、迁移和解离、电子和空穴的传输以及电流的出现。 Ehrenfest 动力学用于研究噻吩：富勒烯堆叠的光激发以及时间依赖性密度函数紧束缚方法。我们的结果显示了供体中电子空穴对的生成及其随后迁移到供体-受体界面。在界面处，电子从噻吩的最低未占据分子轨道 (LUMO) 转移到富勒烯的第二 LUMO。电子和空穴的进一步迁移导致电流的出现。这些发现支持了先前关于电子和振动自由度之间相干耦合的实验证据，并有望激发进一步的工作，探索电子-空穴对（激子）结合和电荷分离和传输的振动耦合之间的相互作用。