Enhancing saturable absorption in a Au-decorated MoS 2 /PEDOT:PSS nanocomposite through plasmon resonance and Pauli blocking

• Published in: Physical chemistry chemical physics : PCCP 2024-03, Vol.26 (12), p.9645-9656
• Main Authors: K, Arjun, C K, Amaljith, B, Karthikeyan
• Format: Article
• Language: English
• ISSN: 1463-9076; 1463-9084
• 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.