Fluorescence and third-order nonlinear optical properties of thermally stable CBPEA dye-doped PMMA/ZnO nanocomposites

摘要

We report the preparation and characterizations of polymethylmethacrylate (PMMA)/zinc oxide (ZnO) doped with 1 -chloro-9,10-bis (phenyl ethynyl) anthracene (CBPEA) dye nanocomposite films by solution casting technique. The nanocomposite films were characterized using UV-Visible, fluorescence emission, DSC, TGA and SEM techniques. The UV-Visible confirms an increase in the absorption wavelength from 280 to 447 nm with increase in the concentration of CBPEA dye. The microstructural and dispersion of dopants were confirmed by FE-SEM studies. TGA and DSC results displayed the thermal stability of the nanocomposite films. The fluorescence spectra show the emission maximum for 1.5 wt% dye at 522 nm shifting towards higher wavelength, and anisotropic plots studies show the faster rotational diffusion with lower value of anisotropy. Further, colour parameter such as colorimetry co-ordinates (x, y), dominate wavelength (λ_d), percentage of colour purity were calculated using 1931(CIE) diagram. The PMMA/ZnO nanocomposite films doped with CBPEA fluorescence dye show blue-green emission. The nonlinear optical (NLO) properties were studied by open and closed aperture Z-scan technique using DPSS continuous wave (CW) laser operating at 532 nm wavelength. The two-photon assisted nonlinear absorption, nonlinear refraction third-order nonlinear optical susceptibility (χ~(3)), and all-optical switching properties were determined. The switchover property of nanocomposites from reverse saturable absorption (RSA) to saturable absorption (SA) behaviour was observed. Therefore, the obtained results suggest that the fabricated films are suitable materials for optoelectronics and nonlinear optical applications.