AC field-induced polymer electroluminescence with single wall carbon nanotubes.
AC field-induced polymer electroluminescence with single wall carbon nanotubes.
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DOI：
10.1021/nl103458g
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发表时间：
2011-01
期刊：
影响因子：
10.8
通讯作者：
Jinwoo Sung;Yeon Sik Choi;S. Kang;S. Cho;Tae-Woo Lee;Cheolmin Park
中科院分区：
文献类型：
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作者：
Jinwoo Sung;Yeon Sik Choi;S. Kang;S. Cho;Tae-Woo Lee;Cheolmin Park
我们开发了一种高性能场致聚合物电致发光（FPEL）器件，该器件由四个堆叠层组成：顶部金属电极/单壁碳纳米管（SWNTs）的薄溶液处理纳米复合薄膜和在交流（AC）电场下工作的荧光聚合物/绝缘体/透明底部电极。通过共轭嵌段共聚物分散剂将少量的swnt高度分散在荧光聚合物基体中，显著提高了EL，并且我们能够实现在±25 V的施加电压和300 kHz的交流频率下，光发射约为350 cd/m(2)的SWNT-FPEL器件。SWNT-FPEL器件的亮度远高于其他基于交流的有机甚至无机el，通常需要至少几百伏的电压。我们的SWNT-FPEL装置发射光是因为在交流电场下，通过双极性碳纳米管依次注入场诱导空穴和电子载流子，然后在共轭有机层中形成激子。场致双极电荷注入为我们的器件提供了很大的材料设计自由度；能级不必在电极和发射层之间对齐，与传统的有机发光二极管相比，注入和运输的载流子的平衡可以改变，从而导致极具成本效益和统一的设备架构，适用于所有红绿蓝荧光聚合物。
We developed a high-performance field-induced polymer electroluminescence (FPEL) device consisting of four stacked layers: a top metal electrode/thin solution-processed nanocomposite film of single wall carbon nanotubes (SWNTs) and a fluorescent polymer/insulator/transparent bottom electrode working under an alternating current (AC) electric field. A small amount of SWNTs that were highly dispersed in the fluorescent polymer matrix by a conjugate block copolymer dispersant significantly enhanced EL, and we were able to realize an SWNT-FPEL device with a light emission of approximately 350 cd/m(2) at an applied voltage of ±25 V and an AC frequency of 300 kHz. The brightness of the SWNT-FPEL device is much greater than those of other AC-based organic or even inorganic ELs that generally require at least a few hundred volts. Light is emitted from our SWNT-FPEL device because of the sequential injection of field-induced holes and then electron carriers through ambipolar carbon nanotubes under an AC field, followed by exciton formation in the conjugated organic layer. Field-induced bipolar charge injection provides great material design freedom for our devices; the energy level does not have to be aligned between the electrode and the emission layer, and the balance of the carrier injected and transported can be altered in contrast to that in conventional organic light-emitting diodes, leading to an extremely cost-effective and unified device architecture that is applicable to all red-green-blue fluorescent polymers.