双层聚合物发光器件中的输运特性研究

Transport Characteristics in the Double Layer Polymer Devices

基于载流子电导是空间电荷限制与空间电荷在器件内部指数减小的假设,通过引入电荷空间分布的特征长度及有效迁移率,并考虑注入电流为热电子电流和隧穿电流,由此对器件的输运特性进行了详细讨论.结果表明电荷空间分布的特征长度对器件中的载流子浓度、电场强度及电流有很大影响;器件功能层厚度对器件的电场强度影响较大,对器件I-V特性影响不大.

Discussed charge transport in the double layer conjugated polymer light-emitting device with thermionic and tunneling charge-carrier injection, considered that the polymer transport properties along the polymer are position dependent, with the charge-carrier mobility being smaller near the electrode/polymer neighborhood. We also assume a charge density distribution that decreases exponentially from this interface. We determine a parameter that indicates how deep material properties are altered. The influences of the characteristic length of the spatial distribution of charge and the thickness of the functional layer on the carrier densities, electric field and current are discussed. The model fits experimental data well, discussed possible reasons for the position dependence of the electrical features of the polymer layer in terms of the device fabrication process.