在荧光材料中掺杂合适的磷光敏化剂,可以大大提高荧光有机电致发光器件(OLED)的效率。选择磷光材料知fac-tris(2-phenylpyridinato-N,C^2′)iridium(Ⅲ)(Ir(ppy)3)分别与荧光材料4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl(DCJTB)、5,6,11,12,-tetraphenylnaphthacene(Rubrene)掺杂作为发光层,当掺杂质量比合适时,磷光材料的发光消失,得到了纯正的荧光材料的发光。同时,对磷光材料的敏化作用及发光机制进行了分析,比较了Ir(ppy)3对两种不同荧光材料的敏化作用强弱,发现Ir(ppy)3对荧光材料Rubrene的敏化作用更强。对影响敏化作用的因素进行了分析,推测其原因与磷光材料和荧光材料的相容性质有关。
It is considered that the efficiency of fluorescent material based organic light emitting diodes can be enhanced by introducing a phosphorescent sensitizer. In the present work, devices with emission layers (EML) of fac-tris(2-phenylpyridinato-N,C^2′) iridium (Ⅲ) (Ir(ppy)3)-sensitized-fluorescent materials were fabricated. Ir(ppy)3 was co-doped with DCJTB and rubrene in PVK matrix, respectively. When the doping ratio was proper, pure emission from fluorescent material can be achieved. Furthermore, the sensitizing mechanism and effect were analyzed. A weak effect between Ir(ppy)3 and DCJTB was found. It was deduced that the weaker sensitizing effect is related to the poor film appearance.