A white phosphor based on oxyfluoride nano-glass-ceramics co-doped with Eu3+ and Tb3+: Energy transfer study

Structural and Photoluminescence Investigations of Tb3+/Eu3+ Co-Doped Silicate Sol-Gel Glass-Ceramics Containing CaF2 Nanocrystals

“…A tune in the excitation wavelength to λ exc = 351 nm also led to the generation of the characteristic emission lines of Tb 3+ ions. Such coexistence of emission lines originated from both optically active dopants is due to the energy transfer process from Tb 3+ to Eu 3+ [ 17 , 18 , 19 , 20 , 21 , 22 ]. In the case of the band recorded in a red spectral scope, a slight shift was observed of a maximum from 620 (XG 1Tb ) to 618 nm (XG 1Tb1Eu ), which was caused by overlapping the weak 5 D 0 → 7 F 2 band of Eu 3+ ions (with a maximum at 615 nm) with the 5 D 4 → 7 F 3 band of Tb 3+ ions (with a maximum at 620 nm).…”

“…The evidence of Tb 3+ /Eu 3+ ET is stated by the shortening of a lifetime from the 5 D 4 state of Tb 3+ in the presence of acceptor ions (Eu 3+ ). It is reported in the literature that the fluorescence decay becomes quicker with the increment of Eu 3+ content, which accelerates the Tb 3+ /Eu 3+ ET and makes it more efficient [ 17 , 18 , 19 , 20 , 21 , 22 ]. Furthermore, a comparative analysis of energy transfer efficiency, η ET , in precursor glasses and glass-ceramics is also carried out to demonstrate the impact of controlled crystallization on Tb 3+ /Eu 3+ ET.…”

“…Moreover, to the best of our knowledge, the investigation of Tb 3+ /Eu 3+ ET in oxyfluoride sol-gel glass-ceramics is rarely described in the available literature. Indeed, it was examined only in SiO 2 -SrF 2 [ 20 ] and SiO 2 -BaGdF 5 [ 45 ] sol-gel nano-glass-ceramics; however, there are no reports on the SiO 2 -CaF 2 system so far. Due to the above reasons, it seems justified to study the Tb 3+ /Eu 3+ ET in silicate sol-gel glass-ceramics containing CaF 2 nanocrystals.…”

Up-conversion white emission and other luminescence properties of a YAG:Yb2O3·Tm2O3·Ho2O3@SiO2 glass-nanocomposite

“…3, inset) attributed to electronic transitions between structural defect levels of amorphous SiO 2 . 29,30 Emission lines of Tm 3+ and Ho 3+ are observed against the wing background. The distinct Ho 3+ bands attributed to 5 S 2 , 5 F 4 / 5 I 8 (peaked at 541 nm, 18 484 cm À1 ) and 5 G 4 / 5 I 6 (at 585 nm, 17 094 cm À1 ) transitions are present only in the spectra of the material thermally treated in the 200-800 C range (curves a-c).…”

“…Its origin is attributed to photon recombinations from numerous defects (as dangling bonds) in the amorphous silica. 29,30 The measured decay prole of the silica luminescence under excitation by the pulse laser at 290 nm is shown in Fig. 8.…”