输运层厚度与迁移率对双层有机发光器件性能的影响

基于一些合理假设与近似，建立了具有欧姆接触载流子注入的双层有机电致发光器件的解析模型．模型中计算参数只有空穴和电子输运层的厚度、迁移率、外加电压及材料参数Fh和Fe，且这些参数都是可以通过测量得到的．研究了材料参数Fh，Fe对器件复合电流密度的影响及空穴输运层厚度和载流子迁移率对器件电场强度和复合电流密度的影响．结果表明：空穴输运层厚度和载流子迁移率引起电场强度的重新分布，进而对复合电流密度产生影响；接触限制电极注入少数载流子的器件可以取得比欧姆接触注入多数载流子的器件更高的复合电流．

Influence of Transport Layer Thickness and the Carrier's Mobilities on the Properties of Bilayer OLEDs

Based on some reasonable approximations, a simple analytic model for the total cell current in bilayer organic light-emitting devices (OLEDs) with Ohmic contacts was presented. This model permitted the semiquantitative analyses of the influence of the most important parameters on the electroluminescence(EL) and cell currents. In particular, the dependence of cell recombination current density on the material parameters Fh , Fe and the dependence of the electric field in hole transport layer(HTL) and electron transport layer(ETL) on the ratio of electron to hole mobilities and on the light-emitting device (LED) geometry were analyzed. It was found that this model could reasonably elucidate the influence of some material parameters on the recombination current density and could provide the methods to optimize the structure and to select suitable electroluminescent materials. The results were in good agreement with both existing experimental data and numerical simulations.