高效率磷光与荧光相结合的白色有机发光器件

制作了一种白色有机电致发光器件(WOLED)。将红光Ir(piq)2(acac)]及绿光Ir(ppy)3]磷光掺杂染料分别掺入到母体CBP中,在2种磷光发光层间插入蓝光材料DPVBi,引入电子传输能力强的BPhen作为电子注入层和空穴阻挡层,通过改变蓝光发光层的厚度,得到了高效率的WOLED,最大电流效率可达17.6cd/A,最大功率效率达13.7lm/W,最大亮度达27525cd/m2,当电压从4V变化到12V时,色坐标从(0.54,0.35)变化到(0.30,0.31),基本处于白光区。器件的特点在于DPVBi的存在阻挡了2种磷光材料间的能量转移,色度可以通过简单地调整DPVBi的厚度,避免使用稀有的蓝光磷光材料和与其相匹配的母体材料,同时又可以保持较高的发光效率。

Efficient white light-emitting device based on phosphorescent emissive layer combining with fluorescent emitter layer

A multiple emissive layer,in which a blue emissive layer is sandwiched between red and green ones,is employed in a white organic light-emitting device.We obtain the efficient white emission from the mixing of red emission from the bis(1-(phenyl)isoquinoline)iridium(ⅡI)acetylanetonate Ir(piq)2(acac)],green emission from the fac tris (2-phenylpyridine) iridium Ir(ppy)3],and blue emission from the NPB or DPVBi,where Ir(piq)2(acac) and Ir(ppy)3 are doped into CBP host,respectively.And we replace phosphorescent blue emissive layer to fluorescent blue material DPVBi in order to avoid using the blue phosphorescent material and the corresponding host materials that are very rare,The device emission color is controlled by varying the thickness of blue emitting layer.The maximum luminance,EL efficiency and power efficiency of the device with the thickness of 8nm DPVBi are 27 525 cd/m2,17.6 cd/A and 13.7 lm/W,respectively.And CIE coordinates of the device vary from (0.54,0.35) at 4 V to (0.30,0.31) at 12V which are general within the white region.DPVBi can prevent the energy transfer between two phosphorescent emitting layers,and the CIE may tune by changing the thickness of DPVBi.