Eu^3+doped TiO2 anatase spheres were obtained by modified sol-gel approach.Spheres(110-250 nm)are composed of smaller(5-15 nm)nanocrystals and exhibit red emission under UV light excitation.Materials were synthesized ...Eu^3+doped TiO2 anatase spheres were obtained by modified sol-gel approach.Spheres(110-250 nm)are composed of smaller(5-15 nm)nanocrystals and exhibit red emission under UV light excitation.Materials were synthesized by multi-step method from glycolated titania alkoxides.Europium doped(1.0 mol%)and non-doped spheres were synthesized.Their optical and structural properties were compared by materials characterization methods,such as X-ray powder diffraction,transmission electron microscopy and PL spectroscopy.Doped TiO2 spheres are crystalline phase pure and exhibit high luminescence intensity.展开更多
Spectroscopic properties of tetragonal LiYbF_4 nanocrystals under high dense NIR excitation at vacuum condition were investigated. White, broad band emission covering whole visible part of the spectrum from LiYbF_4 na...Spectroscopic properties of tetragonal LiYbF_4 nanocrystals under high dense NIR excitation at vacuum condition were investigated. White, broad band emission covering whole visible part of the spectrum from LiYbF_4 nanocrystals was observed. Its intensity strongly depended on the excitation power, excitation wavelength and ambient pressure. Temperature of the nanocrystals under 975 nm excitation was determined as a function of excitation power. Strong photo-induced current was observed from LiYbF_4 pallet. The emission kinetic was analyzed. The mechanism of the anti-Stokes white emission was discussed in terms of the laser-induced charge transfer emission from Yb^（2＋） states.展开更多
文摘Eu^3+doped TiO2 anatase spheres were obtained by modified sol-gel approach.Spheres(110-250 nm)are composed of smaller(5-15 nm)nanocrystals and exhibit red emission under UV light excitation.Materials were synthesized by multi-step method from glycolated titania alkoxides.Europium doped(1.0 mol%)and non-doped spheres were synthesized.Their optical and structural properties were compared by materials characterization methods,such as X-ray powder diffraction,transmission electron microscopy and PL spectroscopy.Doped TiO2 spheres are crystalline phase pure and exhibit high luminescence intensity.
基金supported by National Centre of Science(NCS)Project(Poland)(NCN-2012/06/A/ST5/00212)
文摘Spectroscopic properties of tetragonal LiYbF_4 nanocrystals under high dense NIR excitation at vacuum condition were investigated. White, broad band emission covering whole visible part of the spectrum from LiYbF_4 nanocrystals was observed. Its intensity strongly depended on the excitation power, excitation wavelength and ambient pressure. Temperature of the nanocrystals under 975 nm excitation was determined as a function of excitation power. Strong photo-induced current was observed from LiYbF_4 pallet. The emission kinetic was analyzed. The mechanism of the anti-Stokes white emission was discussed in terms of the laser-induced charge transfer emission from Yb^（2＋） states.
