Pump power induced tunable upconversion emissions from Er³⁺/Tm³⁺/Yb³⁺ions tri-doped SrY₂O₄nanocrystalline phosphors

Synthesis and up-conversion luminescence properties of Er3+/Yb3+ co-doped Sr2CeO4 phosphors

“…Furthermore, Sr 2 CeO 4 has a low phonon energy of 561 cm -1 [21], which is very low compared with that of other oxide host such as Y 3 Al 5 O 12 (850 cm -1 ) [22]. It is well known that a host lattice with low phonon energy will increase the UC emission efficiency due to its low multiphonon relaxation rate [23]. Therefore, we expected that Sr 2 CeO 4 would be a suitable host for UC phosphors.…”

Power driven tunable white upconversion luminescence from Lu2TeO6 tri-doped with Yb3+, Tm3+ and Ho3+

“…This is very close to the standard color coordinates (0.33, 0.33), suggesting that the Yb,Tm,Ho:LTO has a potential use in standard white light sources. The pump power tunable white upconversion emission was also studied in some other systems such as the Yb,Tm,Er and Yb,Tm,Ho tri-doped NaYF 4 , 30 Yb,Tm,Er:SrY 2 O 4 , 31 Yb,Tm,Er:Lu 2 O 3 , 32 and Yb,Tm,Er: LiNbO 3 . 33 Compared with the results of these studies, the tuning range of the white light color coordinates for the Yb, Tm,Ho:LTO system is the broadest, which implies that the Yb,Tm,Ho:LTO would have more potential advanced applications in upconversion based optoelectronic devices.…”

Photoluminescence, TGA/DSC and photocatalytic activity studies of Dy3+ doped SrY2O4 nanophosphors

“…With the help of HRTEM, the morphologies of the formed nanophosphors were analysed, showing that the particles remain nearly spherical with their usual size. [34][35][36] The average particle size is about 49 nm, as shown in Fig. 4.…”

“…From the FE-SEM image, it is clear that the SrY 2 O 4 :Dy 3+ nanophosphors are spherical in nature with quite identical sizes and closely crowded with each other. [34][35][36][37] Also from Fig. 5 it is found that the average phosphor particle size is around 55 nm; these very crowded phosphor particles avoid the scattering of light, creating strong light production and acting as a suitable material for potential applications in the area of lighting.…”

“…In addition to these peaks, there is the presence of small peaks; the source of these peaks may be magnetic dipoles or electric dipoles, aer emitting to the completion levels, which is dependent on the sites of Dy 3+ in the lattice of SrY 2 O 4 , and the type of transfer is determined by selection rules. [34][35][36][37] The observed photoluminescence mechanism is described schematically through the energy level diagram in Fig. 7.…”