Effect of singly, doubly and triply ionized ions on downconversion photoluminescence in Eu3+ doped Na2Sr2Al2PO4Cl9 phosphor: A comparative study

Enhanced photoluminescence in RE (Eu3+, Ce3+ and Sm3+)‐activated Ca10(PO4)F2 phosphors by double or triple ionized mineral doping: a comparative study

“…Excitation bands monitored at 615 nm emission were observed at 281 and 466 nm; the 281 nm excitation band was attributed to typical charge transfer between V 5+ and O 2− in VO 4 3− and the peak at 466 nm in blue region was due to the 7 F 0 → 5 D 2 transition of Eu 3+ ions, showing that this phosphor was suitable for blue light excitation (466 nm). [ 34,35 ] The emission spectra showed one low‐pitched emission band at 584 nm corresponding to orange emission, and due to the 5 D 0 → 7 F 1 transition of Eu 3+ ions, and one high‐pitched band at 615 nm, due to the characteristic emission of Eu 3+ ions from the 5 D 0 → 7 F 2 transition, as shown in Figures 8 and 9. The 5 D 0 → 7 F 1 transition occurred due electric dipole transition, which was very sensitive to local symmetry, therefore transition is allowed only when an Eu 3+ ion occupies a site without an inversion centre.…”

Luminescence study of Sm3+,Eu3+‐doped Y2Zr2O7 host: optical investigation of greenish yellow to red colour tunable pyrochlore phosphor

“…[ 24–26 ] This increase in intensity after doping with Dy 3+ may be due to an internal change in local crystal structure. [ 27,28 ]…”

“…The peak observed at 618 nm was due to the electric dipole 5 D 0 → 7 F 2 transition of the Eu 3+ ion observed in the red region. [ 49,50 ] When comparing all three emission spectra of Eu 3+ , the emission at 534 nm had the higher intensity. The strength of exchange interaction was confirmed for the 534 nm excited spectra.…”

“…[24][25][26] This increase in intensity after doping with Dy 3+ may be due to an internal change in local crystal structure. [27,28] It is well known that four main peaks (222), (400), (440), and (622) are characteristic of a defective fluorite structure. These characteristic peaks can also be indexed based on the pyrochlore structure.…”

Improvement of luminescence properties of NaYF4:Yb3+/Er3+ upconversion materials by a cross‐relaxation mechanism based on co‐doped Ho3+ ion concentrations

“…[ 20,27,28 ] Therefore, photon energy was increased to the 4 S 3/2 energy level, resulting in strong UC green emission. [ 24,29 ] As the Ho 3+ ion concentration increased, the total UC intensity decreased, and the characteristics of Er 3+ ion fluorescence also decreased. Sample f (NaYF 4 :Yb 3+ 0.18 /Er 3+ 0.02 /Ho 3+ 0.03 ) gave a result that matched the NaYF 4 :Yb 3+ /Ho 3+ spectrum characteristics.…”