覆盖层对顶发射白光微型OLED性能的影响研究

Research on Capping Layer for Top-emitting White OLED Micro-display Performance

采用两种覆盖层CPL(Capping layer)材料Alq3和ZnSe制备了顶发射白光有机电致发光器件TE-OLEDs(Top emitting white organic light-emitting diodes),器件结构为ITO/NPB:LiQ(5%)(10 nm)/TCTA(20nm)/FIrpic+3.5%Ir(ppy)3+0.5%Ir(MDQ)2(acac)(25nm)/TPBI(10nm)/LiF(5nm)/Mg:Ag(10%)(12 nm)/CPL。实验结果表明,Alq3和ZnSe作为CPL可以增强TE-OLED器件的出光和调制光谱特性,并且ZnSe作为覆盖层制备的TE-OLED器件色坐标(CIEX,CIEY)随亮度变化更平稳,表现出良好的色稳定性。进一步,通过改变ZnSe厚度来优化器件,当ZnSe为45 nm时,器件获得了最佳的亮度和电流效率,分别为1461 cd/cm2和7.38 cd/A,色坐标为(0.30,0.33)。

We prepared top-emitting white organic light-emitting diode(OLED)devices using Alq3 and ZnSe as capping layers(CPLs).The basic structure of the OLED was ITO/NPB:LiQ(5%)(10 nm)/TCTA(20 nm)/FIrpic+3.5%Ir(ppy)3+0.5%Ir(MDQ)2(acac)(25 nm)/TPBI(10 nm)/LiF(5 nm)/Mg:Ag(10%)(12 nm)/CPL.The brightness and current efficiency of OLED devices fabricated with Alq3 and ZnSe as CPLs are significantly better than those without capping layers.Moreover,the color coordinates(CIEX,CIEY)of the OLED devices prepared with ZnSe CPLs changed more smoothly with brightness,showing good color stability.Further,by changing the ZnSe thickness to optimize the device,when the CPL was 45 nm,the maximum current efficiency and maximum brightness of the device were 7.38 cd/A and 1410 cd/m2,respectively,and the color coordinates were(0.30,0.33).