顶部发射绿色磷光OLED的制备与瞬态性能研究

Research in the fabrication and transient properties of efficient green phosphorescent top emitting OLED

用磷光材料Ir(ppy)3制备了高效率顶部发射绿色有机发光二极管(OLED),器件的结构为:ITO/Ag/NPB/Ir(ppy)3(5wt%):TPBI/TPBI/LiF/Al。研究发现与传统的无微腔结构器件相比顶部发射器件的性能有大幅度提高,其最大效率为18cd/A。通过使用F-P腔,器件的电致发光(EL)寿命由7.6μs降低为7.1μs,有效地缓解了效率随电流密度增大而下降的问题。顶部发射器件EL共振的主峰位于505nm处,发射光谱半峰宽(FWHM)窄化为23nm,色纯度为(x=0.122,y=0.671),发射光随探测角度变化较小。最后,分析了其瞬态光电性能变化原因。

Efficient green phosphorescent top emitting organic electroluminescent（EL） devices with a double metal mirror Fabry-perót microcavity structure are constructed.The configuration of device is ITO/Ag/NPB/Ir（ppy）3（5 wt%）：TPBI/TPBI/LiF/Al.It is found that the device performance is improved greatly.A maximum current efficiency of 18 cd/A is obtained.The EL lifetime is decreased from 7.6 μs to 7.1 μs by the F-P cavity,which relieves the decrease of current efficiency with the increase of current density in traditional phosphorescent devices.In top emitting device,the resonance emission peak is at 505 nm,the FWHM （full width half maximum） is 23 nm,and the CIE coordinates are （x=0.122 and y=0.671）,and the EL emission spectra have minor dependence on detection angle.