有机半导体材料中载流子传输的理论研究

有机半导体光电磁器件研究既有广阔的应用前景也蕴含新的物理机理。实验事实表明有机半导体材料中的电荷输运呈现有别于传统无机半导体的非寻常特性，其自旋传输则具有相当长的相干时间。针对这些特性，其电荷传输机理的理论研究既可丰富物理的认识，也有助于新材料和新器件研制。本项目拟(1)在量子-经典混合的电-声相互作用模型中，唯像补充载流子动力学过程中的退相干和能级弛豫，以符合近平衡的Boltzmann分布，并实现对电场的直流响应及迁移率的计算；(2)从全量子的电-声相互作用模型出发，研究载流子动力学过程中的退相干和能级弛豫；结合上述唯像研究，全面认识有机半导体材料中载流子输运的自洽物理图像；(3)建立包含载流子自旋相互作用的跃迁模型，研究载流子在分子间的非相干跃迁与自旋相互作用的微观机理，探讨自旋相干运动和载流子非相干跃迁结合导致的新现象和新效应，包括磁场效应及其产生的物理条件和材料特性。

It has both the great potential applications and novel physical mechanisms to study the optoelectronic and spintronic devices based on organic semiconducting materials. It has been shown by experiments that the charge transport in organic materials presents unusual features and its spin has a quite long coherent time, for which the physical understanding of its mechanism may give new physics, and should also contribute to the development of new materials and devices. In the project, (1) we complement phenomenologically the decoherence and energy dissipation in carriers’ transport within the quantum-classical mixed electron-phonon interacting model, to meet the Boltzmann distribution for carriers in a process closed to equilibrium, and to achieve the direct current response of external electric field and realize the direct calculation of carrier's mobility; (2) we study the decoherence and energy dissipation in a fully quantum electron-phonon interacting model, and try to obtain a comprehensive picture of carriers’ transport by combining the above phenomenological method in organic semiconducting maters; (3) by constructing a microscopic model for carrier’s intermolecular hopping with the spin interaction, we study the microscopic mechanism of the interplay between the carrier’s incoherent hopping and the coherent spin motion and novel phenomena and effects as its consequence, including the magnetic field effect and the physical conditions or the materials' characteristics required.