中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 22 No. 5 May 2012 |
(State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials,
Southwest University of Science and Technology, Mianyang 621010, China)
Abstract:Erbium-doped BaTiO3 films on LaNiO3/Si substrates were fabricated by sol−gel method. The crystalline structure, morphologies and upconversion (UC) luminescence properties of films were respectively investigated by X-ray diffraction (XRD), atomic force microcopy (AFM) and photoluminescence (PL). The results indicate that both of the microstructure and luminescence are found to be dependent on Er3+ substituting sites. The samples with A-site substitution have smaller lattice constants, larger grains and smoother surface than those with B-site substitution. The photoluminescence spectra show that both of the samples have two stronger green emission bands centered at 528 and 548 nm and a weak red emission band centered at 673 nm, which correspond to the relaxation of Er3+ from 2H11/2, 4S3/2, and 4F9/2 levels to the ground level 4I15/2, respectively. Compared with B-site doped films, A-site doped films have a stronger integrated intensity of green emissions and a weaker relative intensity of red emissions. The differences could be explained by the crystalline quality and cross relaxation (CR) process.
Key words: Er3+ doping; BaTiO3 thin films; upconversion photoluminescence; sol−gel method