National Nanotechnology Center, National Science and Technology Development Agency, Klong Luang, Pathumthani 12120, Thailand.
National Nanotechnology Center, National Science and Technology Development Agency, Klong Luang, Pathumthani 12120, Thailand.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 May 5;125:36-45. doi: 10.1016/j.saa.2013.12.111. Epub 2014 Jan 23.
The electronic structures and photophysical properties of anthracene derivatives as hole-transporting materials (HTM) in OLEDs have been studied by DFT and TD-DFT methods. Thiophene and triphenylamine (TPA) moieties are used as substituents in anthracene based HTMs providing FATn and FAPn compounds (n=1-2), respectively. The calculated electronic levels by B3LYP show proper energy matching of FAPn and hole-injecting layer (HIL), indicating that the hole-transports of the FAPn compounds are better than the FATn compounds. The photophysical properties calculated by TD-B3LYP elucidate that TPA in FAPn compounds acts as electron donating group and induces charge transfer character in the absorptions. Furthermore, the calculated ionization potential (IP), electron affinity (EA) and reorganization energies also revealed that the extended FAP2 compound has the highest charge-transporting ability among the studied compounds. The calculated results are consistent to our experimental observations showing that FAP2 exhibits bright fluorescence with highest quantum yield in electroluminescent devices. Understanding of these properties is useful for further design of new HTMs of desired properties, such as high efficiency and stability.
通过密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）方法研究了蒽衍生物作为有机发光二极管（OLED）空穴传输材料（HTM）的电子结构和光物理性质。噻吩和三苯胺（TPA）部分作为取代基引入蒽基 HTM 中，分别提供了 FATn 和 FAPn 化合物（n=1-2）。B3LYP 计算的电子能级表明 FAPn 和空穴注入层（HIL）之间具有适当的能量匹配，表明 FAPn 化合物的空穴传输性能优于 FATn 化合物。TD-B3LYP 计算的光物理性质表明，FAPn 化合物中的 TPA 作为供电子基团，在吸收中诱导电荷转移特性。此外，计算的电离势（IP）、电子亲和力（EA）和重组能也表明，扩展的 FAP2 化合物在研究的化合物中具有最高的电荷传输能力。计算结果与我们的实验观察结果一致，表明 FAP2 在电致发光器件中表现出最高量子效率的明亮荧光。对这些性质的理解有助于进一步设计具有所需性质的新型 HTM，例如高效率和稳定性。
