Deep-blue and white organic light-emitting diodes based on novel fluorene-cored derivatives with naphthylanthracene endcaps
作者:Ting Zhang、Di Liu、Qian Wang、Renjie Wang、Huicai Ren、Jiuyan Li
DOI:10.1039/c1jm11438g
日期:——
Novel fluorene based deep-blue-emitting molecules with naphthylanthracene endcaps, namely 2,7-di(10-naphthylanthracene-9-yl)-9,9-dioctylfluorene (NAF1) and 7,7′-di(10-naphthylanthracene-9-yl)-9,9,9′,9′-tetraoctyl-2,2′-bifluorene (NAF2), are synthesized by a Suzuki cross-coupling reaction. These materials exhibit excellent thermal and amorphous stabilities, and high fluorescence quantum yield of over 70%. Organic light-emitting devices (OLEDs) using NAF1 or NAF2 as non-doped emitter exhibit bright deep blue electroluminescence with CIE coordinates of (0.15, 0.13) for NAF1, (0.16, 0.13) for NAF2. A maximum power efficiency of 2.2 lm W−1 (4.04 cd A−1, 4.04%) is achieved for NAF1, which is among the highest values ever reported for deep-blue fluorescent OLEDs. A further improved coordinates of (0.15, 0.09) with efficiencies of 3.56 cd A−1 and 2.10 lm W−1 are achieved for NAF1 upon tuning device thickness, which are also among the best data for non-doped deep blue fluorescent OLEDs with a CIE coordinate of y < 0.1. NAF1 serves as excellent host emitter when doped with an orange fluorophore (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran, DCJTB). Upon careful tuning the doping level, the two-emitting-component (NAF1 : DCJTB) OLED realizes efficient white light emission with a power efficiency of 3.01 lm W−1 (7.66 cd A−1), a brightness of 12090 cd m−2, and a standard white light coordinates of (0.33, 0.33). This performance is among the best results ever reported for two-emitting-component white OLEDs based on fluorescent materials.
新的基于氟新烯的深蓝发光分子,具有萘基蒽端帽,分别为2,7-二(10-萘基蒽-9-基)-9,9-二辛基氟新烯(NAF1)和7,7′-二(10-萘基蒽-9-基)-9,9,9′,9′-四辛基-2,2′-双氟新烯(NAF2),通过铃木交叉偶联反应合成。这些材料展现出优异的热稳定性和无定形稳定性,并且荧光量子产率超过70%。使用NAF1或NAF2作为非掺杂发射体的有机发光器件(OLED)展示出亮丽的深蓝电致发光,NAF1的CIE坐标为(0.15, 0.13),NAF2的CIE坐标为(0.16, 0.13)。NAF1的最大功率效率为2.2 lm W−1(4.04 cd A−1,4.04%),是迄今为止深蓝荧光OLED中报道的最高值之一。通过调整器件厚度,NAF1的CIE坐标进一步提高到(0.15, 0.09),效率为3.56 cd A−1和2.10 lm W−1,这也在非掺杂深蓝荧光OLED中达到了y < 0.1的最佳数据。NAF1作为掺入橙色荧光体(4-(二氰甲烯)-2-叔丁基-6-(1,1,7,7-四甲基喹啉-9-烯)-4H-吡喃,DCJTB)时表现出优异的宿主发射体。在仔细调整掺杂水平后,两组分发光器件(NAF1 : DCJTB)实现了高效的白光发射,功率效率为3.01 lm W−1(7.66 cd A−1),亮度达到12090 cd m−2,标准白光坐标为(0.33, 0.33)。这一性能是基于荧光材料的双发射组分白OLED中迄今为止报道的最佳结果之一。