Structure and Luminescence of New Red‐Emitting Materials‐Eu³⁺‐Doped Triple Orthovanadates NaALa(VO₄)₂ (A = Ca,Sr,Ba)

Abstract

The new red‐emitting phosphors of Eu3+‐doped triple orthovanadates NaALa(VO4)2 (A = Ca, Sr, Ba) were prepared by the high‐temperature solid‐state reaction. The formation of single phase compound with isostructural structure of Ba3(VO4)2 was verified through X‐ray diffraction (XRD) studies. The photoluminescence excitation and emission spectra, the fluorescence decay curves and the dependence of luminescence intensity on doping level were investigated. The phosphor can be efficiently excited by near UV and blue light to realize an intense red luminescence (613 nm) corresponding to the electric dipole transition 5D0→7F2 of Eu3+ ions. Their potential applications as red‐emitting phosphors for solid‐state lighting were evaluated in comparison with the Eu3+‐doped lanthanum orthovanadate LaVO4 and other reported references. The luminescence was discussed in detail on the base of the crystal structures. The luminescence thermal stability on temperature was investigated and the thermal activated energy was calculated. The phosphors can be suggested to be a potential red‐emitting phosphor for the application on white LEDs under irradiation of near‐UV or blue chips.

Phase formations and tunable red phosphors of LiYb1−Eu (MoO4)2 (x = 0.01–1)

“…The excitation spectra consist of broad charge transfer (CT) band and some narrow lines. The CT band peaking around 315 nm is originated from the charge transfer transition of O 2-→ Eu 3+ [23][24][25]. The CT band extends with the full-width at half-maximum of about 6970 cm -1 and shows no significant change in spectral shape for x = 0.01-1.0 as shown in Fig.…”

Luminescence of the self-activated vanadate phosphors Na2LnMg2V3O12 (Ln=Y, Gd)

“…The vanadates based compounds not only meet the requirement but also serve as a typical luminescent host [12,13]. Usually, vanadates offer broad and intense excitation spectra covering from n-UV to visible region as well as emission ranging from blue to red due to their charge transfer (CT) transitions in the VO 4 3 À [14,15].…”

Key chemical parameters related to the width of the charge transfer band and the emission intensity of 5D0→7F2 in Eu3+ doped Ln2O3

“…A large number of Eu 3+ -activated inorganic phosphors have been extensively investigated due to their wide application in luminescence and display [1][2][3][4][5][6][7][8][9]. The red emission phosphors are predominantly due to 5 D 0 -7 F 2 electric dipole transition around 610-630 nm of Eu 3+ [10].…”