使用荧光染料TBPe和Ir(ppy)2acac、R-4B两种光染料,采用蓝/红绿双发光层的结构,并结合TPBi对空穴的有效限制作用,制备了结构为ITO/MoO3(X nm)/ADN:(2%)TBPe(30nm)/CBP:Ir(ppy)2acac(14%):R-4B(2%)(5nm)/TPBi(10nm)/Alq3(30nm)/LiF(1nm)/Al(100nm)的磷光与荧光复合的白光OLED,其中,MoO3的厚分别为0、15、20、30和40nm,通过改变MoO3的厚度调控载流子的注入能力,使用空穴阻挡层提高光效;通过测量其电压、电流、亮度、色坐标和电致发光(EL)光谱等参数,研究不同厚度的MoO3对器件发光性能的影响。结果表明,在MoO3厚为20nm的情况下,器件的效率滚降最为平缓。在电压分别为8、9、10、11、12和13V时,器件的色坐标分别为(0.31,0.33)、(0.30,0.33)、(0.29,0.33)、(0.29,0.33)、(0.29,0.33)和(0.29,0.33),具有较高的稳定性,原因为采用蓝/红绿双发光层结构更有利于蓝光的出射,且使用ADN主体材料掺杂蓝色荧光染料TBPe作为蓝光发光层降低三重态-三重态湮灭几率。研究还发现,在电压为11V、器件的亮度为9 744cd/m2和电流密度为11.50mA/cm2时,最大器件的电流效率为7.0cd/A。
By using the fluorescent dye TBPe and two kinds of phosphorescent dye Ir(ppy)2 acac, R-4B, with blue/red and green double-emitting-layer structure, combined with the effective hole restriction of TPBi, the fluorescent-phosphorescent hybrid white organic light-emitting diodes (OLEDs) were prepared with the structure of ITO/MoO3 (X nm) / ADN: (2 % ) TBPe (30 nm) / CBP: Ir (ppy) 2 acac ( 14 % ) : R-4B (2G) (5 nm)/TPBi(10 nm)/ Alq3 (30 nm)/LiF(1 nm)/Al(100 nm). The influence of MoO3 thickness on luminescence properties of the devices is studied. The results show that when MoOs thickness is 20 nm,the efficiency of the device rolls off flatly. When the voltage is 8 V,9 V,10 V,11 V,12 V,13 V,14 V, 15 V,color coordinates of the devices are respectively (0.31, 0. 33), (0. 30, 0. 33), (0.29, 0.33), (0. 29,0.33),(0.29,0.33),(0. 29,0.33) and they have high stability. The reason is that the blue/red and green light emitting layer structure has more benefit to blue light emitting,and using ADN doping blue fluorescent dyes TBPe as the blue light emitting layer can reduce the triplet-triplet annihilation probability. When the voltage is 11 V, brightness of the device is 9 744 cd/m2. When the current density is 11.50 mA/cm2 ,the maximum current efficiency is 7.0 cd/A.