使用R-4B新型红色磷光染料作为掺杂剂,制作了结构为ITO/MoO3(10)/NPB(40)/TCTA(10)/CBP∶R-4B(x)/BCP(10)/Alq3(40)/LiF/Al的红色磷光器件,结合TCTA和BCP(电子和空穴阻挡材料),通过调节R-4B的掺杂比例,对器件的发光性能和发光机理进行了研究。结果表明,掺杂比例为6%时,得到光效和颜色稳定性较好的器件。在电压为4V时,电流密度为0.045mA/cm2,亮度为3.57cd/m2,最大电流效率为19.48cd/A;在电压分别为5、10和15V时,色坐标分别为(0.60,0.35)、(0.64,0.34)、(0.64,0.35)。分析认为,一方面,R-4B的发光机理主要有主体材料CBP对R-4B的能量传递及载流子直接注入R-4B形成激子;另一方面,TCTA和BCP的作用为对发光层内载流子、激子的阻挡及使空穴、电子更有效注入发光层。
The authors have investigated luminescent properties and [uminescence mechamsm oy aajusung the doping ratio and combing with TCTA and BCP (electron and hole barrier material). The structure was ITO/ MoO3(10)/NPB(40)/TCTA (10)/CBP: R-4B(x)/BCP (10)/Alq3 (40)/LiF/A1, R-4B was new red phosphor dopant. It was found that the better efficacy and color stability device was obtained, utilizing 6% doping ratio. The maximum current efficiency was 19.48cd/A, current density was 0. 045mA/cm2 , brightness was 3.57cd/ m2 at 4V. The CIE..y coordinates of the device showed (0.60, 0.35), (0.64, 0.34) and (0.64, 0.35) at 5,10 and 15V, separately. The improved performance was attributed to the mainly luminescent mechanism which in- cluding the energy transfer from the host materials CBP to R-4B and the carrier direct injection. Moreover, TC- TA and BCP blocked the carrier and exciton of emitting layer, efficiently.