Dominant role of organic dye on Mn: ZnS/PMMA polymer nanocomposites: Structural, thermal, linear, and nonlinear optical properties for optoelectronic and photonic applications

Abstract

In this work, we investigated structural, thermal, linear, third order nonlinear (NLO), and optical limiting (OL) properties of an organic dye filled Mn: ZnS/PMMA polymer nanocomposite (PNCs). The structural properties were determined using fourier transform infrared spectroscopy in attenuated total reflectance mode (ATR-FTIR) and X-ray diffraction (XRD) techniques. The surface morphology of samples studied using scanning and transmission electron microscope (SEM and TEM) photographs. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) helps to determine the thermal stability of prepared PNCs. The linear optical properties studied using UV-Visible spectroscopy. The samples better absorption spectra in the range 360 and 362 nm, and the optical energy band gap is reduced due to dye concentration increases. The samples exhibit strong fluorescence emission at 485 nm, confirming the blue emission. The fluorescence anisotropy (r) and polarisation (P) studies helps study molecular orientation of PNCs and energy transfer (ET) mechanism was explained using fluorescence lifetime decay curves. The third order nonlinear optical (NLO) properties were investigated using an open and closed aperture Z-scan technique with a DPSS continuous wave (CW) laser at 532 nm. The two-photon assisted nonlinear absorption (β), nonlinear refraction (n2) third-order nonlinear optical susceptibility (χ (3)) were investigated. The obtained β, n2 and χ (3) are found to be in the order ∼10−5 cmW−1, 10−8 cm2W−1 and 10−7 esu, respectively for all the samples. Further, they exhibited strong optical limiting behaviour with lower limiting thresholds (∼kW/cm2). The prepared PNCs exhibits strong linear and NLO properties showing that the PNCs could be suitable for optoelectronic and photonic applications.