Liu Lihui, Wu Lei, Yang Hao, Ge Honggang, Xie Juxuan, Cao Kun, Cheng Gang, Chen Shufen
State Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
Hong Kong Quantum AI Lab Limited, 17 Science Park West Avenue, Pak Shek Kok 999077, Hong Kong SAR, China.
ACS Appl Mater Interfaces. 2022 Jan 12;14(1):1615-1625. doi: 10.1021/acsami.1c21591. Epub 2021 Dec 30.
Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is one of the most prospering transparent conductive materials for flexible optoelectronic devices, which arises from its nonpareil features of low-cost solution processability, tunable conductivity, high transparency, and superior mechanical flexibility. However, acidity and hygroscopicity of PSS chains cause a decrease in conductivity, substrate corrosion, and device degradation. This work proposes a facile and effective direct doping strategy of sodium 3-methylsalicylate to enhance the conductivity, alleviate the acidity, and improve the stability of PEDOT:PSS electrodes, simultaneously. Owing to the formation of weaker acid and PSS-Na, PSS chains are disentangled from the coiled PEDOT:PSS complexes, leading to the phase separation of PEDOT:PSS and the formation of fibril-like PEDOT domains. Eventually, the sodium 3-methylsalicylate-modified PEDOT:PSS electrode is employed in flexible organic light-emitting diodes with an outstanding external quantum efficiency of up to 25%. The improved performance is attributed to the more matched work function and the as-formed interfacial dipole. The sodium 3-methylsalicylate-modified PEDOT:PSS electrode with high conductivity and transmittance, superior stability in the air as well as good mechanical flexibility has the potential to be the most promising transparent conductive material for flexible optoelectronic device applications.
聚（3,4-乙撑二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT:PSS）是用于柔性光电器件最具发展前景的透明导电材料之一，这源于其无与伦比的低成本溶液可加工性、可调电导率、高透明度和卓越的机械柔韧性等特性。然而，PSS链的酸性和吸湿性会导致电导率降低、基板腐蚀和器件性能退化。这项工作提出了一种简便有效的3-甲基水杨酸钠直接掺杂策略，以同时提高PEDOT:PSS电极的电导率、减轻酸性并改善其稳定性。由于形成了较弱的酸和PSS-Na，PSS链从盘绕的PEDOT:PSS复合物中解开，导致PEDOT:PSS相分离并形成纤维状的PEDOT域。最终，3-甲基水杨酸钠改性的PEDOT:PSS电极被应用于柔性有机发光二极管中，其外部量子效率高达25%，表现出色。性能的提升归因于更匹配的功函数和形成的界面偶极。具有高电导率和透光率、在空气中具有卓越稳定性以及良好机械柔韧性的3-甲基水杨酸钠改性的PEDOT:PSS电极，有潜力成为用于柔性光电器件应用最具前景的透明导电材料。
