Dynamics of charge separation at an organic donor-acceptor interface

Article

关键词: HOT EXCITON DISSOCIATION;    SOLAR-CELLS;    POLYMER;    ENERGY;    HETEROJUNCTIONS;    ELECTRONS;    STATES;   

DOI  :  10.1103/PhysRevB.90.115420

来源: SCIE

【 摘 要 】

The key process in organic photovoltaic cells is the charge separation at organic donor-acceptor interfaces. However, exactly how the charges separate into free charge carriers still remains a puzzle. We present here simulations of the electron dynamics of this process using a nonadiabatic Ehrenfest method. From these simulations, we give a direct illustration of the charge separation process. The results show that the delocalization of the electronic states involved plays a critical role in order to overcome the Coulomb attraction of the charge transfer (CT) exciton. Charge separation only occurs for sufficiently strong intermolecular interactions. Alternatively, the CT exciton relaxes into a bound polaron pair. The results also show that the excess energy of the hot CT exciton facilitates the charge separation process to a certain degree.

【 授权许可】

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