Chen Yong-Hua, Ma Dong-Ge, Sun Heng-Da, Chen Jiang-Shan, Guo Qing-Xun, Wang Qiang, Zhao Yong-Biao
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Department of Macromolecular Science and Engineering, School of Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
Light Sci Appl. 2016 Mar 11;5(3):e16042. doi: 10.1038/lsa.2016.42. eCollection 2016 Mar.
Organic light-emitting diodes (OLEDs) are driven by injected charges from an anode and a cathode. The low and high work function metals are necessary for the effective injection of electrons and holes, respectively. Here, we introduce a fully novel design concept using organic semiconductor heterojunctions (OSHJs) as the charge injectors for achieving highly efficient OLEDs, regardless of the work functions of the electrodes. In contrast to traditional injected charges from the electrodes, the injected charges originate from the OSHJs. The device performance was shown to be significantly improved in efficiency and stability compared to conventional OLEDs. Attractively, the OLEDs based on OSHJs as charge injectors still exhibited an impressive performance when the low work function Al was replaced by air- and chemistry-stable high work function metals, such as Au, Ag, and Cu, as the cathode contact, which has been suggested to be difficult in conventional OLEDs. This concept challenges the conventional design approach for the injection of charges and allows for the realization of practical applications of OLEDs with respect to high efficiency, selectable electrodes, and a long lifetime.
有机发光二极管（OLED）由从阳极和阴极注入的电荷驱动。低功函数和高功函数金属分别是有效注入电子和空穴所必需的。在此，我们引入一种全新的设计理念，即使用有机半导体异质结（OSHJ）作为电荷注入器来实现高效OLED，而无需考虑电极的功函数。与传统的从电极注入电荷不同，注入的电荷源自OSHJ。与传统OLED相比，该器件的性能在效率和稳定性方面有显著提高。吸引人的是，当用空气和化学稳定的高功函数金属（如Au、Ag和Cu）作为阴极接触取代低功函数Al时，基于OSHJ作为电荷注入器的OLED仍表现出令人印象深刻的性能，而在传统OLED中这被认为是困难的。这一概念挑战了传统的电荷注入设计方法，并使得在高效率、可选择电极和长寿命方面实现OLED的实际应用成为可能。
