Structural and photoluminescence properties of red-light emitting YVO4:Eu3+ phosphor synthesized by combustion and solid-state reaction techniques: a comparative study

Abstract

In this work, Eu 3? -doped YVO 4 phosphors were prepared via the solid-state reaction and the combustion method and the role of the synthesis process on the structural and emission properties of YVO 4 :Eu 3? was investigated. Combustion synthesis yielded tetragonal phase with the space group I4 1 /amd at a relatively low temperature and within short duration. The infrared spectra confirmed the characteristic bands of Y-O and V-O at around 450 and 830 cm -1 , while the samples prepared by combustion route exhibited C-O band and O-H-O bending vibrations at 1376 and 1637 cm -1 , respectively. The band gap energy of YVO 4 , prepared by different methods, was found in the range of 3.6-3.73 eV. Upon UV excitation, the Eu 3? -activated samples exhibited characteristic red-orange emission lines generated from 5 D 0 ? 7 F 1,2 transitions of Eu 3? ions, respectively. The red-to-orange emission intensity ratio was found to be around 4.6 for all samples and proved to be competitive with the commercially available red phosphors. However, Y 1-x Eu x VO 4 phosphors, synthesized by solid-state reaction technique, exhibited elevated Eu 3? solubility and higher emission intensity than the samples prepared by combustion route owing to the larger crystallite size and minor C-O and O-H bonds. The critical concentration of Eu 3? ions for the maximum emission was estimated to be 2.0 and 0.5 mol% for the samples obtained by solid-state reaction and combustion method, respectively. The present phosphors were observed to be effectively excitable via the broad range of UV lights and were proved to be compatible with the UV LEDs.

Luminescence investigation of a cerium‐doped yttrium vanadate phosphor

“…A weak peak at 450 cm −1 could be attributed to yttrium–oxygen bonds. The solid peak at 806 cm −1 was due to movement of VO 4 . The 1635 cm −1 area unit corresponded to OH stretching vibration modes for coordinated water.…”

“…From Figure and in Table it can be seen that as crystal size diminishes, dislocation density and strain values increase. This difference could be due to enhancement of the surface effect . From exploratory outcomes it was inferred that there was no considerable shift in the peak positions of PXRD patterns of Ce‐doped YVO 4 .…”

“…From Figure and in Table lattice parameters of Ce‐YVO 4 are demonstrated, where (a = 7.061 Å) and was observed to be same as that of pure YVO 4 (a = 7.063 Å). This is because the ionic range of Ce 3+ (1.02 Å) was almost equals to that of the Y 3+ (0.88) ion. Scherer's equation is given as: D = (kλ/βcosθ).…”

“…Scherer's equation is given as: D = (kλ/βcosθ). Dislocation density (δ) was calculated using the relationship δ = 1/D 2 , Strain was calculated using the relationship ɛ = β cos θ /4 …”

High Efficient YVPO4 Luminescent Materials Activated by Europium

“…Most of them have high thermal stability and chemical activity. Particularly, phosphors based on rare-earth activated yttrium phosphates and vanadates are some of the most promising compounds of this type [4][5][6][7][8][9][10][11].…”