|
Title: |
Synthesis and Photoluminescence of (La1-x,Tbx)2O2S Nano-Phosphors by Co-Precipitation Method |
|
Source: |
Proceedings of the 7th National Conference on Functional Materials and Applications (FMA 2010 E-BOOK)
(pp 37-41)
|
|
Author(s): |
Jing-bao Lian, School of Mechanical Engineering, Liaoning Shihua University, Fushun, 113001, China
Bing-xin Wang, School of Mechanical Engineering, Liaoning Shihua University, Fushun, 113001, China
Xu-dong Sun, Key Lab for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004, China
Xiao-dong Li, Key Lab for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004, China |
|
Abstract: |
(La1-x,Tbx)2O2S nano-phosphors were synthesized by calcined the (La1-xTbx)2(OH)4SO4?nH2O precursors in hydrogen atmosphere using commercially available La2O3、Tb4O7、H2SO4 and NaOH as the starting materials . The formation and characterization of (La1-x,Tbx)2O2S nano-phosphors were investigated by means of FT-IR, XRD, FE-SEM and PL spectra. The results confirmed that the as synthesized precursor was composed of (La1-x,Tbx)2(OH)4SO4?nH2O crystalline state and could be transformed into single phase (La1-x,Tbx)2O2S by calcined at 800 ℃ for 1 h in hydrogen atmosphere. The synthesized (La1-xTbx)2O2S phosphor particles are quasi-spherical and well dispersed, with a mean particle size of about 50-70 nm. Under 260 nm UV light excitation, the emission spectrum of (La0.98,Tb0.02)2O2S nano-phosphor is composed of a series of peaks centered at 491 nm, 545 nm, 588 nm and 621 nm, corresponding to the 5D4→7Fj (J = 6～3) transitions of Tb3+ ions, respectively. The predominant green emission peak located at 545 nm is attributed to the 5D4→7F5 transition of Tb3+ ions. The decay processes of (La0.98,Tb0.02)2O2S nano-phosphor include a fast and a slow process and have a double exponential decay behavior. With increasing calcination temperature, the lifetime of (La0.98,Tb0.02)2O2S nano-phosphor becomes shorter due to increasing oxygen and sulfur vacancies in hydrogen atmosphere.
|