主要通过红绿磷光材料R-4B和GIr1掺杂的方法,制备了黄光OLED器件,器件结构为ITO/MoO3(X)/NPB(40nm)/TCTA(10nm)/CBP:GIr1 14%:R-4B2%(30nm)/BCP(10nm)/Alq3(40nm)/LiF(1nm)/Al(100nm),TCTA和BCP分别为电子和空穴阻挡材料,同时结合TCTA和BCP对载流子的高效阻挡作用,研究了MoO3对器件效率和稳定性的影响。发现当增加MoO3的厚度为90nm时,在较大的电压范围内,器件都具有较高的效率和色坐标稳定性。在电流密度为7.13mA/cm2时,器件达到最高电流效率29.2cd/A,亮度为2081cd/m2;电流密度为151.7mA/cm2时,获得最高亮度为24430cd/m2,电流效率为16.0cd/A;器件色坐标稳定性较好,当电压为5、10、15V时,色坐标分别为(0.5020,0.4812)、(0.4862,0.4962)、(0.4786,0.5027)。器件性能的改善主要归因于载流子注入与传输的平衡以及阻挡层对发光区域的有效限定。
The yellow organic light-emitting devices(OLED) were fabricated by evaporation method using R-4B and GIr1(red and green phosphorescent materials).The device structure used here was ITO/MoO3(X)/NPB(40nm)/ TCTA(10nm)/CBP: GIr1 14%:R-4B2%(30nm)/BCP(10nm)/Alq3(40nm)/LiF(1nm)/Al(100nm),TCTA and BC P were electron and hole block layer separately.We investigated the efficiency and chromatic-stability characteristics of these fabricated devices through the method of optimization of the thickness of the MoO3.The optimum performance of OLED was achieved by the application of 90nm MoO3.The maximum EL efficiency and luminance reached 29.2cd/A at 7.13mA/cm2,2081 and 24430cd/m2 at 151.7cd/m2,16.0cd/A respectively.Moreover,commission international De L'eclairage(CIE) coordination of(0.5020,0.4812),(0.4862,0.4962),(0.4786,0.5027) were obtained at 5,10,15V.The enhanced efficiency and good chromatic stability were attributed to the balanced carrier injection and transport as well as the effective confinement to the light-emitting region with barrier layer.