Nonlinear Optical Studies of Conjugated Organic Dyes for Optical Limiting Applications
作者:AA Ummu Habeeba、M. Saravanan、T.C. Sabari Girisun、S Anandan
DOI:10.1016/j.molstruc.2021.130559
日期:2021.9
due to its enhanced charge transfer property in the excited state. Nonlinear optical absorption was studied by open-aperture Z-scan technique using Nd:YAG laser (532 nm, 10 Hz, 9 ns). Here HC, DTBT exhibit a genuine two-photon absorption (TPA) process while PCTB possesses sequential TPA involving excited-state absorption. All dyes exhibit energy-absorbing optical limiting behaviour ascribed due to the
由不同的供体/受体部分即己基咔唑(HC),4,7-二噻吩-2-基)苯并[c] [1,2,5]噻二唑(DTBT)和Poly-4制成的D-π-A共轭有机染料通过偶联反应制备了-(5-(9-己基-9H-咔唑-2-基)噻吩-2-基)苯并[c] [1,2,5]噻二唑(PCTB)。FTIR,NMR和质谱用于确定合成化合物的分子结构。HC和DTBT均显示出较宽的光学透射率窗口(400-600 nm),在UV区域具有最大吸收率。但是,PCTB的能带结构发生了变化,在可见光区(448 nm)吸收较宽。密度泛函理论(DFT)计算表明,随着共轭作用的扩展,HOMO和LUMO之间的带隙减小,并且在UV-Vis吸收光谱中发生红移。-1是由于其在激发态下增强的电荷转移特性。通过使用Nd:YAG激光(532 nm,10 Hz,9 ns)的开孔Z扫描技术研究了非线性光学吸收。在这里,HC,DTBT表现出真正的双光子吸收(