The luminescence enhancement of Eu3+ ion and SnO2nanocrystal co-doped sol-gel SiO2 films

摘要

SnO2 nanocrystal and rare-earth Eua+ ion co-doped SiO2 thin films are prepared by sol-gel and spin coating methods.The formation of tetragonal rutile structure SnO2 nanocrystals with a uniform distribution is confirmed by X-ray diffraction and transmission electron microscopy.Fourier transform infrared spectroscopy is used to investigate the densities of the hydroxyl groups,and it is found that the emission intensity from the 5Do-7F2 transitions of the Eu3+ ions is enhanced by two orders of magnitude due to energy transfer from the oxygen-vacancy-related defects of the SnO2 nanocrystals to nearby Eu3+ ions.The influences of the amounts of Sn and the post-annealing temperatures are systematically evaluated to further understand the mechanism of energy transfer.The luminescence intensity ratio of Eu3+ ions from electric dipole transition and magnetic dipole transition indicate the different probable locations of Eu3+ ions in the sol-gel thin film,which are further discussed based on temperature-dependent photoluminescence measurements.