Microstructural and Photoluminescence Properties of Tin Dioxide Modified by Electron Beam Irradiation

A modified technique was developed by electron beam irradiation to prepare tin dioxide (SnO₂) nanocrystals using the sol–gel method. SnO₂ nanoparticles were radiated under a 1,400 KGy dose. The morphology and microstructure of the SnO₂ nanocrystals were investigated by X-ray diffraction, high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The results indicate that the irradiated SnO₂ nanoparticles have better crystallinity than unirradiated SnO₂ nanoparticles, and the resulting nanocrystals have a tetragonal rutile crystalline structure. The HRTEM image proves that the average grain size is about 4 nm, and the clear lattice fringes indicate the improvement of SnO₂ nanocrystals after irradiation. The Raman spectrum shows that there are new peaks at 535 cm⁻¹ and 691 cm⁻¹. The optical properties of SnO₂ nanoparticles were characterized by ultraviolet-visible (UV-vis) and photoluminescence spectrophotometers. The band gap energy of the irradiated SnO₂ was 3.29 eV smaller than that of the unirradiated SnO₂ due to size effects and some defects of SnO₂ nanocrystals. This work provides a novel approach for the improvement of SnO₂ nanocrystals. The optical properties of the irradiated SnO₂ nanomaterials are also expected to improve.