摘要
使用绿色磷光材料GIr1和红色磷光材料R-4B作为掺杂剂,制备了一种黄色磷光有机电致发光器件(OLED),其结构为ITO/MoO3(60nm)/NPB(40nm)/TCTA(xnm,x=0、5、10和15)/CPB:GIr1:R-4B(30nm,14%,2%)/BCP(10nm)/Alq3(40nm)/LiF(1nm)/Al(100nm)。其中x=0,5,10,15nm。通过在发光层与空穴传输层之间增加电子阻挡层TCTA,使器件的效率得到提高。当TCTA厚为10nm时,起亮电压为4V左右,器件的最大发光效率为20.2cd/A,最高亮度可以达到21840cd/m2,器件的色坐标为(0.42,0.53)。器件的EL主峰位于524nm和604nm。并且当电流密度为2.49mA/cm2时,10nm厚的TCTA电子阻挡层的器件发光效率是不加入TCTA的器件发光效率的2倍。发光效率的提高是由于电子阻挡层的加入限制了空穴传输层NPB的发光,从而使更多的激子在发光层中复合。
Yellow phosphorescent organic lighting emitting devices were fabricated by using green phos- phorescent dye Girl and red phosphorescent dye R-4B doped with the host material CBP as the emitting layer. The structure of the devices is ITO/MoOa （60 nm）/NPB（40 nm）/TCTA （x nm）/CPB.. Girl.. R- 4B（30 nm,14%,2 %） /BCP（10 nm） /Alq3 （40 nm）/LiF （1 nm）/Al（100 nm） ,in which x is equal to 0, 5,10 and 15. The current efficiency of yellow phosphorescent organic lighting emitting devices has been improved by inserting TCTA as an electron blocker between the emitting layer and the hole transport layer. It is found that the best thickness is 10 nm for the TCTA layer,the turn-on voltage of this device is 4 V,the highest current efficiency is 20.2 cd/A,the highest luminance of the device is 21840 ed/m2 , the commission internationale de I＇Eclairage （CIE） color coordinate is （0.42,0.53） and the EL spectra show two prominent peaks at 524 nm and 604 nm. Moreover,at a current density of 2.49 mA/cm2 ,the current efficiency of the device with 10 m-thick TCTA as the electron blocker layer is approximately two times greater than that of the device without TCTA layer. The current efficiency of device is en- hanced because of an electron blocker confining the emitting of NPB, which leads to more excitions com- bining in the emissive layer.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2013年第2期234-238,共5页
Journal of Optoelectronics·Laser
基金
国家自然科学基金(61076066)
陕西科技大学博士基金(BJ09-07)
陕西科技大学自然科学基金(ZX09-31)资助项目
