载流子迁移率对单层有机发光二极管复合效率的影响

Effects of carrier mobilities on recombination efficiency in single layer organic diodes

建立了在单层有机发光二极管中电场强度不太大 (E≤ 10 4 V cm)的情况下 ,载流子注入、传输和复合的理论模型 .通过求解非线性Painleve方程得出了电场强度随坐标变化的解析函数关系式以及电流密度随电压变化关系 ,给出了电流密度以及器件的复合效率在不同的载流子迁移率情况下随电压变化关系图像 .结果表明 ,复合效率受载流子迁移率影响较大 ,在器件中多数载流子应具有较低的迁移率 ,而少数载流子应具有较高的迁移率 ,这样有利于载流子的注入和传输 ,从而可提高发光效率 .并且得出当空穴迁移率大于电子迁移率时 ,复合区域偏向阴极 。

A model for carriers injection,transport and recombination in single layer organic light emitting diodes was presented.The electric field contribution,the relationship between current density and the applied voltage,and the recombination efficiency were obtained by solving the nonlinear Painleve equation.When the majority of carriers had lower mobility,the carriers were easy to get injection and transport,and the device efficiency could be improved.If the hole mobility was larger than the electron mobility,the recombination zone moved towards cathode,and vice versa.