Well-Balanced Ambipolar Organic Single Crystals toward Highly Efficient Light-Emitting Devices
Well-Balanced Ambipolar Organic Single Crystals toward Highly Efficient Light-Emitting Devices
复制标题
平衡良好的双极性有机单晶可用于高效发光器件
DOI：
10.1002/adfm.202002422
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发表时间：
2020-09-09
影响因子：
19
通讯作者：
Sun, Hong-Bo
中科院分区：
文献类型：
--
作者：
An, Ming-Hui;Ding, Ran;Sun, Hong-Bo
载流子迁移率是有机半导体在电子和光电子器件中应用的关键问题之一。有机单晶具有比非晶薄膜高得多的载流子迁移率。然而，具有不平衡的空穴和电子输运能力的单极性特性一直是有机单晶基器件高性能的瓶颈。在这里，良好平衡的双极性有机单晶是通过混合n型和p型分子与保持单晶结构来开发的。双极单晶的载流子迁移率通过调节混合比来控制，并且可以实现几乎相等的空穴和电子迁移率。通过采用双极晶体作为红色发射体并五苯的混合主体，实现发射层内高效的激子限制和能量转移，展示了高效的基于单晶的有机发光器件（OLED）。结果表明，器件的最大亮度为5467 cd·m（-2），电流效率为2.82cd·A（-1），这是迄今为止有机单晶基OLED器件的最高亮度和电流效率。在这项工作中的策略，以操纵的有机单晶的电荷传输特性的有机单晶在光电子学的实际应用迈出了重要的一步。
Carrier mobility is one of the key issues for applications of organic semiconductors in electronic and optoelectronic devices. Organic single crystals possess much higher carrier mobility compared to amorphous films. However, unipolar properties with unbalanced hole and electron transporting ability have been a bottleneck for the high performance of organic single crystal-based devices. Here, well-balanced ambipolar organic single crystals are developed by mixing of n- and p-type molecules with maintained single-crystalline structures. Carrier mobility of the ambipolar single crystals is manipulated by tuning the mixing ratio, and nearly equal hole and electron mobility can be achieved. Highly efficient single crystal-based organic light-emitting devices (OLEDs) are demonstrated by employing the ambipolar crystals as the mixed host for a red emitter pentacene to realize efficient exciton confinement and energy transfer within the emissive layer. As a result, maximum luminance of 5467 cd m(-2)and current efficiency of 2.82 cd A(-1)are achieved, which represents, to the best of the authors' knowledge, the record performance for the organic single crystal-based OLEDs to date. The strategy to manipulate the charge-transport properties of the organic single crystals in this work represents a significant step toward practical applications of the organic single crystals in optoelectronics.