Influence of Eu3+, Bi3+ co-doping content on photoluminescence of YVO4 red phosphors induced by ultraviolet excitation

White light emitting from YVO4/Y2O3:Eu3+,Bi3+ composite phosphors for UV light-emitting diodes

“…When the concentration of Eu 3 þ ion exceeded 0.01 mol, the emission of Bi 3 þ ion (540 nm) remarkably decreased. This phenomenon has been reported by Park [24]. In addition, the doping of Bi 3 þ into YVO 4 :Eu 3 þ system caused the excitation band edge to shift toward the longer wavelength (from 350 nm to 365 nm) due to the low energy absorption involving the metal-to-metal charge transfer band [25,26].…”

“…Moreover, when monitored at 540 nm, only a broad excitation band centered at 335 nm attributed to the charge transfer transition between Bi 3 þ 6s and V 5 þ 3d was obtained. The excitation spectrum monitored at 620 nm showed a strong broad band centered at about 320 nm attributed to the V 5 þ -O 2À charge transfer transition, and three weak sharp peaks at 396, 467 and 534 nm which are attributed to the 7 F 0 -5 L 6 , 7 F 0 -5 D 2 and 7 F 0 -5 D 1 transitions of Eu 3 þ ion, respectively [24]. Therefore, by exciting the YVO 4 matrix both Eu 3 þ and Bi 3 þ ions can generate luminescence efficiently via energy transfer from the host matrix (VO 4 3À ) to the activated ions.…”

Synthesis and luminescence properties of Bi3+-doped YVO4 phosphors

“…Because of the introduction of Bi 3+ ions, the (2 0 0) diffraction peaks at 2Â = 25 • shift slightly toward lower 2Â values with respect to the standard card. This observation results from the fact that the ionic radius of Y 3+ (0.088 nm) is smaller than that of Bi 3+ (0.196 nm) [21]. Obviously, the introduction of Bi 3+ ions did not influence the crystal structure of the host matrix, indicating that we have synthesized successfully the YVO 4 host lattice.…”

Energy transfer process and optimum emission studies in luminescence of core–shell nanoparticles: YVO4:Eu–YVO4 and surface state analysis

“…There are many contradictory papers regarding optimum efficiency for red emission of Eu 3+ observed due to the charge transfer process via Eu-O or V-O [43][44][45]. There is need to see such reports by taking up samples prepared with and without core-shell formation.…”