Facile synthesis and multicolor luminescent properties of uniform Lu2O3:Ln (Ln=Eu3+, Tb3+, Yb3+/Er3+, Yb3+/Tm3+, and Yb3+/Ho3+) nanospheres

• Published in: Journal of colloid and interface science 2012-02, Vol.368 (1), p.165-171
• Main Authors: Li, Rumin, Gai, Shili, Wang, Liuzhen, Wang, Jun, Yang, Piaoping
• Format: Article
• Language: English
• Subjects: Chemistry; Decay; Direct current; emissions; energy-dispersive X-ray analysis; Exact sciences and technology; Fourier transform infrared spectroscopy; General and physical chemistry; irradiation; Lu2O3; Luminescence; nanocrystals; Nanospheres; photoluminescence; Precipitation method; Scanning electron microscopy; thermal analysis; thermogravimetry; transmission electron microscopy; Ultraviolet; Upconversion; Urea; X-ray diffraction; X-rays
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2011.10.026

[Display omitted] ► A facile precipitation method was used to prepare uniform Lu2O3:Ln nanospheres. ► The samples exhibit multicolor down-conversion and up-conversion luminescence. ► The possible formation mechanism was well investigated. ► The color of the phosphors was tuned by doping different rare earth ions. Multicolor Lu2O3:Ln (Ln=Eu3+, Tb3+, Yb3+/Er3+, Yb3+/Tm3+, and Yb3+/Ho3+) nanocrystals (NCs) with uniform spherical morphology were prepared through a facile urea-assisted homogeneous precipitation method followed by a subsequent calcination process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectrum (EDS), Fourier transformed infrared (FT-IR), thermogravimetric and differential thermal analysis (TG–DTA), and photoluminescence (PL) spectra as well as kinetic decays were employed to characterize these samples. The XRD results reveal that the as-prepared nanospheres can be well indexed to cubic Lu2O3 phase with high purity. The SEM images show the obtained Lu2O3:Ln samples consist of regular nanospheres with the mean diameter of 95nm. And the possible formation mechanism is also proposed. Upon ultraviolet (UV) excitation, Lu2O3:Ln (Ln=Eu3+ and Tb3+) NCs exhibit bright red (Eu3+, 5D0→7F2), and green (Tb3+, 5D4→7F5) down-conversion (DC) emissions. Under 980nm NIR irradiation, Lu2O3:Ln (Ln=Yb3+/Er3+, Yb3+/Tm3+, and Yb3+/Ho3+) NCs display the typical up-conversion (UC) emissions of green (Er3+, 4S3/2,2H11/2→4I15/2), blue (Tm3+, 1G4→3H6) and yellow-green (Ho3+, 5F4, 5S2→5I8), respectively.