有机半导体薄膜中的载流子传输特性研究

Abstract

在有机发光二极管中，载流子的注入和传输特性直接影响器件的性能，由于有机半导体分子结构及其薄膜形态的多样性和掺杂体系中分子-分子之间相互作用的不同行为，使有机半导体的传输特性变得更为复杂。因此，深入系统地研究有机半导体中载流子的传输行为，对建立传输特性与器件性能的关系，改进器件性能具有非常重要的意义。本论文以掺杂和非掺杂的有机电子传输材料以及共混材料体系为研究对象，用阻抗和电流-电压特性方法系统地研究了它们薄膜中载流子的传输特性。论文的具体工作内容如下： 1. 研究了不同厚度Alq3薄膜的电子传输特性。稳态电流-电压特性研究表明，Alq3薄膜的电子传输符合陷阱呈幂指数分布的空间电荷限制电流模型，总的陷阱密度约为8.6×1017 cm-3。导纳法测定的Alq3薄膜的电子迁移率（10-7 ~ 10-5 cm2V-1s-1）与薄膜厚度、电场强度相关。当薄膜厚度小于150 nm时，电子迁移率随电场增...In organic light emitting diodes, the carriers injection and transport properties directly affect the performance of the devices. In organic semiconductors, the charge transport characteristics become more complex because of the variety of molecular structures and film morphologies and the different behaviors of the interactions between molecules. Therefore, the systematical investigation on the charge transport characteristics in organic semiconductors is very important for establishing the relationship between the transport properties and device performance, and improving the performance of the devices. In this thesis, we have systematically investigated the carrier transport properties in doped and undoped organic electron-transport materials and blends by admittance spectroscopy techni..