K Arjun, C K Amaljith, B Karthikeyan
Nanophotonics Laboratory, Department of Physics, National Institute of Technology, Thiruchirappalli-620 015, India.
Department of Electro Optics Engineering, Ben Gurion University of the Negev, Israel.
Phys Chem Chem Phys. 2024 Mar 20;26(12):9645-9656. doi: 10.1039/d3cp06153a.
We have effectively demonstrated a technique for substantial alteration of the nonlinear saturable absorption (SA) properties in nanocomposite films (NCF) composed of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS) and molybdenum disulfide (MoS) decorated with gold nanoparticles (AuNPs). This control is achieved by adjusting the AuNP concentration on the MoS surface and varying the input pulse energy of the laser. The simple drop-casting method is used to create the nanocomposite films (NCFs) on a glass substrate with different amounts of Au-decorated MoS. The Kramers-Kronig equations are employed for determining the refractive index and extinction coefficient values of the resulting NCFs. Nonlinear investigations reveal that adding Au-decorated MoS to pure PEDOT:PSS alters its optical nonlinearity. Surface plasmon resonance and Pauli blocking have been observed in Au-decorated MoS/PEDOT:PSS NCFs. This increases NCF's saturable absorption. An open aperture Z-scan method is utilized to study nonlinear optics, with excitation achieved using a nanosecond (ns) pulsed laser operating at a 532 nm wavelength. The findings reveal the noteworthy saturable absorption characteristics of the NCFs.
我们已经有效地展示了一种技术，可对由掺杂聚（4-苯乙烯磺酸盐）的聚（3,4-乙撑二氧噻吩）（PEDOT:PSS）和装饰有金纳米颗粒（AuNPs）的二硫化钼（MoS）组成的纳米复合薄膜（NCF）中的非线性饱和吸收（SA）特性进行实质性改变。这种控制是通过调整MoS表面的AuNP浓度以及改变激光的输入脉冲能量来实现的。采用简单的滴铸法在玻璃基板上制备具有不同量Au装饰MoS的纳米复合薄膜（NCF）。利用克莱默斯-克朗尼格方程来确定所得NCF的折射率和消光系数值。非线性研究表明，向纯PEDOT:PSS中添加Au装饰的MoS会改变其光学非线性。在Au装饰的MoS/PEDOT:PSS NCF中观察到了表面等离子体共振和泡利阻塞。这增加了NCF的饱和吸收。采用开孔Z扫描方法研究非线性光学，使用波长为532 nm的纳秒（ns）脉冲激光进行激发。研究结果揭示了NCF值得关注的饱和吸收特性。
