制备了结构为：ITO/MoO3(40 nm)/NPB(40 nm)/TCTA(10 nm)/CBP: Ir(ppy)2acac(x%)(30 nm)/BCP(10 nm)/Alq3(40 nm)/LiF(1 nm)/Al(100 nm)的器件，Ir(ppy)2acac为绿色磷光染料，x分别为4%、6%、8%、10%。通过调节绿色磷光染料的掺杂浓度，对器件的发光性能进行了研究，发现在掺杂浓度为8%，亮度为490 cd/m2,器件获得最高电流效率为69.43 cd/A，相比4%的器件高出27.5%。分析原因是掺杂浓度越高，载流子在绿色染料上复合的几率越高; CBP与Ir(ppy)2acac的LUMO能级均为2.5 eV,注入主体CBP上的电子可以直接传递给掺杂染料，避免电子对掺杂染料传递过程中的能量损失; 较高的掺杂浓度更有利于载流子的传输。然而，较高的掺杂浓度会引起三线态激子的猝灭效应。另外，由于TCTA、BCP为载流子阻挡材料，具有较高的三线态能量，可以将载流子和激子限制在发光层内。

The device was prepared with the structure: ITO/MoO3 (40 nm)/NPB (40 nm)/TCTA (10 nm)/CBP: Ir (ppy)2 acac (x %)(30 nm)/BCP(10 nm)/Alq3(40 nm)/LiF(1 nm)/Al(100 nm).Ir (ppy)2 acac was the green phosphorescent dyes, x were 4%, 6%, 8% and 10% relatively.Luminous performances of the devices were studied by adjusting the doping concentration of green phosphorescent dyes. With 8% doping concentration and 490 cd/m2 luminance, the highest current efficiency of 69.43 cd/A was achieved, its maximal current efficiency was beyond 27.5% compared with 4% doping device .The reasons were as follows: firstly, the higher doping concentration means the higher opportunity of compounding of the carriers in the emitting layer; secondly, since CBP and Ir (ppy)2 acac were both 2.5 eV at LUMO energy level, electrons can directly transit from the main body CBP to the doping dye Ir (ppy)2 acac, avoid energy loss in the process of electron transmission into dye doping.High doping concentration has more advantage on the transmission of carriers, however, highly doping concentration would cause triplet exciton quenching. In addition, TCTA and BCP are carrier blocking materials, which had higher triplet energy, and thus excitons could be limited in the light-emitting layer.