High performance fluorescent and phosphorescent organic light-emitting diodes based on a charge-transfer-featured host material
High performance fluorescent and phosphorescent organic light-emitting diodes based on a charge-transfer-featured host material
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DOI：
10.1016/j.orgel.2015.03.006
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发表时间：
2015-06
影响因子：
3.2
通讯作者：
Xu Wang;Jie Zhou;Juan Zhao;Zhiyun Lu;Junsheng Yu
中科院分区：
文献类型：
--
作者：
Xu Wang;Jie Zhou;Juan Zhao;Zhiyun Lu;Junsheng Yu
以具有电荷转移特性的化合物6-{3，5-双-[9-（4-叔丁基苯基）-9H-咔唑-3-基]-苯氧基}-2-（4-叔丁基苯基）-苯并[de]异喹啉-1，3-二酮为基质，制备了荧光和磷光有机电致发光器件，并系统研究了这两种器件的电致发光特性。根据光致发光量子产率（ηpl），发现荧光和磷光OLED的外量子效率都超过了它们的理论极限。基于对电致发光特性的分析，荧光和磷光OLED的高器件性能归因于有效的能量转移和三重态能量上转换，而磷光OLED中也涉及直接激子形成。此外，由于主体分子上附着了空间位阻体，使得主体膜具有较高的热稳定性和形态稳定性，从而使荧光和磷光染料的掺杂浓度都较高。这些结果表明，具有电荷转移功能的材料是一种很有前途的有机发光材料。
Fluorescent and phosphorescent organic light-emitting diodes (OLEDs) were fabricated using a charge-transfer-featured compound, 6-{3,5-bis-[9-(4-t-butylphenyl)-9H-carbazol-3-yl]-phenoxy}-2-(4-t-butylphenyl)-benzo[de]isoquinoline-1,3-dione, as a host, and the electroluminescent (EL) characteristics of these two kinds of OLEDs were systematically studied. According to the photoluminescent quantum yields (ηpl), it was found that the external quantum efficiencies of both fluorescent and phosphorescent OLEDs were exceeding their theoretical limits. Based on the analysis of EL characteristics, the high device performance of fluorescent and phosphorescent OLEDs was attributed to both efficient energy transfer and triplet energy up-conversion, while direct exciton formation was also involved in phosphorescent OLEDs. In addition, the host film possessed high thermal and morphological stabilities due to the attachment of steric bulks on host molecule, resulting in the high doping concentration for both fluorescent and phosphorescent dyes. These results indicated that charge-transfer-featured material could be the promising host for both fluorescent and phosphorescent OLEDs.