Study the possibility of using thin films of ZnO as an effective medium for random laser

Thin films of ZnO were successfully prepared on glass substrates with different thicknesses by sol-gel method by using zinc acetate dehydrate as precursor. The surface of thin films morphology from were studied by AFM micrographs, the structural properties of the obtained ZnO thin film are studied using X-ray diffraction spectra and their elemental analysis by X-ray energy dispersion spectroscopy (EDX). Moreover, optical properties and emission of ZnO nano thin film were evaluate during ultraviolet-visible-infrared and photoluminescence spectra. The AFM investigations have revealed that the morphology of the films is smooth and homogeneous specially for the high thickness and the grains produced on the surface take the form of nano rods with an average diameter of 240nm. Structural analysis by X-ray diffraction showed that the deposited films have a preferred orientation along the direction (112) and are relatively uniform with average crystal size 19nm, while the EDX spectrum showed that the elemental composition of these films is zinc oxide. The spectrophotometer Ultraviolet -Visible confirms that it is possible to get good transparent ZnO films with a transmission of 77 to 92% in the infrared. The values of optical gaps Eg vary between 3.273 - 3.256 eV. The peak of photoluminescence exhibited a visible emission peak at 616nm that refers to possibility of using thin films as an effective medium of random laser.

تحضير ودراسة بنيوية لأيروجيل أكسيد السيليسيوم بطريقة Sol-gel المستخدم كعازل أو كحفاز في عمليات تنقية المياه

In this research, several samples of silicon oxide were prepared in the form of aerogel and xerogel, starting from different raw materials and using different drying methods. Where a part of the samples was prepared using aqueous sodium silicate (glass water) (Na2SiO3) as a raw material, which is an economical and cheap material, while the rest of the samples were prepared using tetraethoxysilane (TEOS). Some of these samples were surface modified before drying using Trimethylchlorosilane, which is high Price (TMCS) by replacing the surface silanol groups (Si-OH) with alkyl. As for the remaining samples, which were prepared without surface modification, we succeeded in obtaining aerogel with a lower preparation cost and very close characteristics to the samples prepared by surface modification.

Preparation and Caractarization Of Silica Aerogel By Using Sol-gel method

During this study, various types of silicon oxide were prepared as aerogel and xerogel using multiple precursors and different drying technics. Some of these samples were prepared from Sodium silicate (waterglass) Na2SiO3 as a precursor which is a cheap material, while others were prepared using tetraethoxysilane (TEOS).

The Effect of Annealing on the Crystalline Structure of TiO2 Thin Films

The thin films of TiO2 were prepared by the Sol-Gel, on glass subtracts by using the following initial solutions: trichlorethylene titanium, ethanol, sodium hydroxide and hydrochloric acid and distilled water. The films were annealed at temperatures(200- 300- 400-500)c° for 1 hour. The structure of the prepared and annealed films were studied by XRD. The XRD rusltes showed that the films prepared crystallize according to orthorhombic Structure.Lattice constants were calculated and it was found that it was consistent with the data JPCDS and with some scientific works.