界面复合物改善绿光磷光电致发光性能的研究

Investigation on enhanced electroluminescent performance of green phosphorescent devices via interfacial electroplex

采用绿色磷光材料Ir(ppy)3掺入TCTA中形成TCTA∶Ir(ppy)3发光层,研究了TCTA/TPBi界面复合物对其发光性能的影响.实验结果表明:相较不能形成界面复合物的器件[CBP∶Ir(ppy)3],界面复合物有助于改善器件的发光亮度、效率等性能.TCTA∶Ir(ppy)3中TCTA与TPBi形成界面复合物,一定程度上扩展了激子复合区域,有助于改善激子复合概率,同时,界面复合物较小的单重态-三重态能级差使其三重态激子能量可以通过共振能量传递给Ir(ppy)3发光体,减少能量损失,从而改善器件性能.

In order to investigate the effect of electroplex formed at the interface of TCTA/TPBi on the device performance,the phosphorescent devices were prepared by doping Ir(ppy)3 emitter into TCTA.The experimental results demonstrated that the electroplex forming were favorable for improving the device luminance and efficiency compared to the electroplex free device(CBP-hosted device).Specifically,the exciton recombination region was broadened and the probability of exciton recombination was improved to a certain extent due to the formation of TCTA/TPBi electroplex in the TCTA-hosted device.At the same time,due to relatively small single-triplet gap of electroplex,the energy of triplet electroplex could be transferred to Ir(ppy)3 emitter through F rster resonance energy transfer,leading to a reduction of energy loss and thus improvement of device properties.