Sun Yuanhui, Xu Shipan, Hang Huaiteng, Xi Jun, Dong Hua, Jiao Bo, Zhou Guijiang, Yang Xiaolong
School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, Xi'an Jiaotong University Xi'an 710049 China
School of Electronic Science and Engineering, Xi'an Jiaotong University Xi'an 710049 China.
Chem Sci. 2024 Apr 30;15(22):8506-8513. doi: 10.1039/d4sc01812e. eCollection 2024 Jun 5.
The modulation of emission color is one of the most critical topics in the research field of organic light-emitting diodes (OLEDs). Currently, only two ways are commonly used to tune the emission colors of OLEDs: one is to painstakingly synthesize different emitters with diverse molecular structures, the other is to precisely control the degree of aggregation or doping concentration of one emitter. To develop a simpler and less costly method, herein we demonstrate a new strategy in which the emission colors of OLEDs can be continuously changed with UV light during the device fabrication process. The proof of concept is established by a chromene-based Ir(iii) complex, which shows bright green emission and yellow emission before and after UV irradiation, respectively. Consequently, under different durations of UV irradiation, the resulting Ir(iii) complex is successfully used as the emitter to gradually tune the emission colors of related solution-processed OLEDs from green to yellow. Furthermore, the electroluminescent efficiencies of these devices are unaffected or even increased during this process. Therefore, this work demonstrates a distinctive point of view and approach for modulating the emission colors of OLEDs, which may prove great inspiration for the fabrication of multi-colored OLEDs with only one emitter.
发光颜色的调制是有机发光二极管（OLED）研究领域中最关键的课题之一。目前，通常只有两种方法用于调节OLED的发光颜色：一种是精心合成具有不同分子结构的不同发光体，另一种是精确控制一种发光体的聚集程度或掺杂浓度。为了开发一种更简单、成本更低的方法，在此我们展示了一种新策略，即在器件制造过程中，OLED的发光颜色可以通过紫外光连续变化。基于色烯的Ir(III)配合物确立了这一概念验证，该配合物在紫外光照射前后分别呈现亮绿色发射和黄色发射。因此，在不同的紫外光照射持续时间下，所得的Ir(III)配合物成功用作发光体，将相关溶液处理OLED的发光颜色从绿色逐渐调节为黄色。此外，在此过程中这些器件的电致发光效率未受影响甚至有所提高。因此，这项工作展示了一种用于调制OLED发光颜色的独特观点和方法，这可能为仅用一种发光体制备多色OLED提供巨大的启发。
