Ambipolar Transporting 1,2‐Benzanthracene Derivative with Efficient Green Excimer Emission for Single‐Layer Organic Light‐Emitting Diodes
Ambipolar Transporting 1,2‐Benzanthracene Derivative with Efficient Green Excimer Emission for Single‐Layer Organic Light‐Emitting Diodes
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DOI：
10.1002/adom.201200024
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发表时间：
2013-02
影响因子：
9
通讯作者：
Lian Duan;J. Qiao;Yong-duo Sun;De-qiang Zhang;Guifang Dong;Liduo Wang;Y. Qiu
中科院分区：
文献类型：
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作者：
Lian Duan;J. Qiao;Yong-duo Sun;De-qiang Zhang;Guifang Dong;Liduo Wang;Y. Qiu
单层有机电致发光二极管(OLED)因其具有简化工艺、降低成本等潜在优势而备受人们的青睐。然而，高性能单层OLED在文献中很少见，因为它们需要具有平衡的电子和空穴迁移率、高荧光量子产率和与两个电极匹配的良好能级的双极传输材料。在本工作中，我们设计并合成了一种具有双极传递性的苯并[4-(2，2-二苯基乙烯基)苯基]苯并[7，12-双-[4-(2，2-二苯基乙烯)苯基]苯并[BDPBan]，它没有任何空穴和电子传输的结构基元。由于电子和空穴可以在相邻的苯并茂基团之间以相似的空间范围进行分子间跳跃，因此获得了高于10−3cm2/vs的平衡的空穴和电子迁移率。尽管分子间的强相互作用促进了BDPBAN浓溶液和薄膜中准分子的形成，但制备的高效非掺杂单层有机电致发光器件具有很强的绿光发射。以90 nm BDPBAN为发射层的器件的峰值电流效率为11.4cd/A：超过了根据光致发光量子产额计算的常规上限。
Single‐layer organic light‐emitting diodes (OLEDs) are highly desired due to their potential advantages such as simplifying the fabrication process and lowering the cost. However, high‐performance single‐layer OLEDs are rare in the literature as they require bipolar transporting materials with balanced electron and hole mobilities, high fluorescent quantum yields, and good energy levels matching both electrodes. In this work, a bipolar transporting benzanthracene derivative, namely 7,12‐bis‐[4‐(2,2‐diphenylvinyl)‐phenyl] benzanthracene (BDPBan), is designed and synthesized without any structural motifs for hole and electron transport. As electrons and holes can perform intermolecular hopping to similar spatial extents between the adjacent benzanthracene moieties, well‐balanced hole and electron mobilities higher than 10−3 cm2/Vs are achieved. Though the strong intermolecular interactions facilitate the formation of excimers in concentrated solutions and thin films of BDPBan, efficient undoped single‐layer OLEDs are fabricated with strong green emission from the excimers. A device with 90 nm BDPBan as the emitting layer shows a peak current efficiency of 11.4 cd/A: beyond the conventional upper limit calculated based on the photoluminescence quantum yield.