Facile deposition of nanostructured Rhodamine-6G/FTO optical system thin films for optical limiting

Thin films of Rhodamine-6G were fabricated with different thicknesses by utilizing the spin-coating technique. The used substrate was the Fluorine-doped tin oxide (FTO) for deposition the studied films on it. The technique of X-ray diffraction (XRD) was applied to detect the structural properties of the investigating Rhodamine-6G/FTO thin films. The analysis of Rhodamine 6G/FTO film surface morphology was achieved by the aid of the atomic force microscopy (AFM) technique. Spectral distribution of transmittance, reflectance, and absorbance in the wavelength range (300–2500 nm) was used to explore both of linear properties in addition to the nonlinear optical characteristics of Rhodamine-6G/FTO. All the investigated samples appeared to have an indirect allowed transition. The parts of the complex dielectric constants, real and imaginary parts, were specified. Further, the third-order nonlinear susceptibility (χ⁽³⁾) and the nonlinear refractive index (n²) were estimated. The optical limiting was examined using laser; He–Ne of 632.8 nm and solid-state green of 533 nm. It was found that the normalized power increased with decreasing the thickness of the Rhodamine 6G/FTO thin films. Rhodamine 6G/FTO is a promising optical system for optoelectronic applications.