蓝光磷光微腔有机电致发光器件特性的研究

Characteristics of blue phosphorescent microcavity organic electroluminescent light emitting device

使用典型蓝色磷光材料Firpic作为磷光金属微腔有机电致发光器件(OLED)的发光层,以高反射的Al膜作为阴极顶电极和半透明的Al膜作为阳极底电极,其结构为Glass/Al(15nm)/MoO3(30nm)/NPB(40nm)/mCP:Firpic(30nm,x%)/BCP(10nm)/Alq(20nm)/LiF(1nm)/Al(100nm),x%为Firpic的掺杂质量分数,分别为4%、6%、10%、12%和14%。实验制备了不同的OLED,比较了测量角度和不同掺杂浓度对OLED发光特性的影响。结果显示,对发光面积为0.8cm2的器件,测量角度的不同导致蓝光辐射波长蓝移,色坐标发生变化,器件的510nm和472nm两个峰值变化不相同,随着角度的增大,较大的峰值不断衰减,而较小的峰值不断增强;并且,当掺杂浓度为12%时,OLED得到最好的发光性能,12V电压驱动下有最大亮度18 870cd/m2,说明此时的主客体间能量转移最充分。

The blue phosphor Firpic-based electro-phosphorescent metallic microcavity organic light-emit- ting device （OLED） employs a structure of glass/Al （15 nrn）/MoO3 （30 nm）/NPB （40 nm）/mCP：Fir- pic （30 nm,x%）/BCP（lO, nm）/Alq（20 nm）/LiF（1 nm）/Al（100 nm）,in which x% （4%,6%,10%, 12 %, 14 % ） is the doping mass fraction of Firpic, We prepared different OLEDs and compared the influ- ence of measuring angle and dopant concentration on the luminescence properties of OLEDs. The results show that for the devices with light-emitting area of 0. 8 cme ,the difference of measuring angles results in shift of blue emission and changes of color coordinates. There were two peaks of the devices, which are at 510 nm and 472 nm. Their variations are different. The larger peak is attenuated while the smaller peak is continuously enhanced with the increase of the measuring angle. Furthermore, when the doping concentration is 12% ,the OLED has the best performance. The device has the maximum brightness of 18 870 cd/m2 under 12 V,which implies the energy transfer between host and guest is the fullest.