Symalla Franz, Friederich Pascal, Massé Andrea, Meded Velimir, Coehoorn Reinder, Bobbert Peter, Wenzel Wolfgang
Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Hermann von Helmholtz-Platz 1,76344 Eggenstein-Leopoldshafen, Germany.
Department of Applied Physics and Institute for Complex Molecular systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Phys Rev Lett. 2016 Dec 30;117(27):276803. doi: 10.1103/PhysRevLett.117.276803. Epub 2016 Dec 29.
Charge transport in disordered organic semiconductors is generally described as a result of incoherent hopping between localized states. In this work, we focus on multicomponent emissive host-guest layers as used in organic light-emitting diodes (OLEDs), and show using multiscale ab initio based modeling that charge transport can be significantly enhanced by the coherent process of molecular superexchange. Superexchange increases the rate of emitter-to-emitter hopping, in particular if the emitter molecules act as relatively deep trap states, and allows for percolation path formation in charge transport at low guest concentrations.
无序有机半导体中的电荷传输通常被描述为局域态之间非相干跳跃的结果。在这项工作中，我们关注用于有机发光二极管（OLED）的多组分发光主体-客体层，并使用基于多尺度从头算的模型表明，电荷传输可以通过分子超交换的相干过程得到显著增强。超交换提高了发射体到发射体的跳跃速率，特别是当发射体分子作为相对较深的陷阱态时，并且在低客体浓度下的电荷传输中允许形成渗流路径。
