Laser Densification of Prepared SiO2 Sol-Gel Thin Films

SiO2 nanostructure is synthesized by the Sol-Gel method and thin films are prepared using dip coating technique. The effect of laser densification is studied. X-ray Diffraction (XRD), Fourier Transformation Infrared Spectrometer (FTIR), and Field Emission Scanning Electron Microscopy (FESEM) are used to analyze the samples. The results show that the silica nanoparticles are successfully synthesized by the sol-gel method after laser densification. XRD patterns show that cristobalite structure is observed from diode laser (410 nm) rather than diode laser (532 nm). FESEM images showed that the shape of nano silica is spherical and the particles size is in nano range (? 100 nm). It is concluded that the spherical nanocrystal structure of silica thin films is successfully densified by Doide laser (410 nm).

I. Patterning of silicalite-1 films using CO2 laser ablation. II. Impact of deposition and laser densification of silicalite-1 films on their optical characteristics

Nanostructured materials represent an intriguing foundation on which to build new devices for applications in electronics, photonics, energy storage, and biological/chemical analysis. The standard methods used to pattern such devices are based on typical microfabrication techniques, which involve multiple complex and time-consuming steps with several limitations. Here, we present a simple, flexible alternative to both techniques: CO2 laser ablation. We demonstrate the effects of this technique on a model zeolite thin film system, pure-silica MFI (silicalite-1), to evaluate its potential for patterning complex, multicrystalline, nanostructured materials. Using this technique, we demonstrate that it is possible to make 3D structures in these films, such as channels of varying width (82-611.98 [mu]m), depth (2.58-7.13 [mu]m), separation distance (minimum 25 [mu]m), and edge effects, by varying laser power, spot size, and raster speed. The resulting randomly and b-oriented films of thickness 94.324-550.89 nm showed the ability to reach a range of refractive indices (1.327-1.678), depending on film orientation and deposition technique. The intensities of their IR and Raman absorption regions indicate an increase in crystallinity with CO2 laser irradiation from 10 to 20% power, and then a decrease above 30%. Determining these fundamental optical properties will allow us to explore the functionality of these materials for a wider array of applications in optoelectronics, where nanostructured materials can make a significant difference in scale, cost, efficiency, and overall performance.