Triple molybdate scheelite-type upconversion phosphor NaCaLa(MoO₄)₃:Er³⁺/Yb³⁺: structural and spectroscopic properties

Abstract

Triple molybdate NaCaLa(MoO):xEr,yYb (x = y = 0, x = 0.05 and y = 0.45, x = 0.1 and y = 0.2, x = 0.2 and y = 0) phosphors were successfully synthesized for the first time by the microwave sol-gel method. Well-crystallized particles formed after heat treatment at 900 °C for 16 h showed a fine and homogeneous morphology with particle sizes of 2-3 μm. The structures were refined by the Rietveld method in the space group I4/a. The optical properties were examined comparatively using photoluminescence emission and Raman spectroscopy. Under excitation at 980 nm, the NaCaLa(MoO):0.1Er,0.2Yb and NaCaLa(MoO):0.05Er,0.45Yb particles exhibited a strong 525 nm emission band, a weaker 550 nm emission band in the green region, and three weak 655 nm, 490 nm and 410 nm emission bands in the red, blue and violet regions. The pump power dependence and Commission Internationale de L'Eclairage chromaticity of the upconversion emission intensity were evaluated in detail.

NUV light induced visible emission in Er3+‐activated NaSrLa(MoO4)O3 phosphors for green LEDs and thermometer

“…29,36 For example, Lim and co-workers observed excellent luminescence properties in NaCaLa(MoO 4 )O 3 :Er 3+ ,Yb 3+ phosphors. 37 A similar phenomenon was also observed in NaSrLa(MoO 4 ) O 3 :Er 3+ ,Yb 3+ compounds. 38 Considering the above discussion and the fact that the NaSrLa(MoO 4 )O 3 structure has not been thoroughly investigated, the Er 3+ -activated NaSrLa(MoO 4 )O 3 was selected as a representative sample to verify the dual-functional applications of the rare-earth ion-activated molybdates in pc-LED devices and non-contact optical thermometry.…”

“…Recently, molybdates have been extensively investigated due to their excellent luminescent properties, high stability and relatively low synthesis temperature . For example, Lim and co‐workers observed excellent luminescence properties in NaCaLa(MoO 4 )O 3 :Er 3+ ,Yb 3+ phosphors . A similar phenomenon was also observed in NaSrLa(MoO 4 )O 3 :Er 3+ ,Yb 3+ compounds …”

Gd2Zr3(MoO4)9 microwave dielectric ceramics with trigonal structure for LTCC application

“…In the previous Raman evaluation of complex molydates, it was demonstrated that Raman mode with highest wavenumber was ascribe to shortest Mo–O bond vibration according to relation between bond length and predicted of ν (cm −1 ) . Furthermore, in double molybdates, the modes wavenumbers observed over 130‐190 cm −1 are classified as translations of Gd ions …”

“…58 Furthermore, in double molybdates, the modes wavenumbers observed over 130-190 cm −1 are classified as translations of Gd ions. [59][60][61][62]…”

Synthesis and Upconversion Luminescence in LaF3:Yb3+, Ho3+, GdF3: Yb3+, Tm3+ and YF3:Yb3+, Er3+ obtained from Sulfide Precursors

“…The UC spectrum of YF 3 :Yb 3+ , Er 3+ contains five distinctly detectable emission bands of Er . Especial interest is the presence of 4 H 9/2 – 4 I 15/2 transition that requires participation of at least three pump photons for the excitation of 4 H 9/2 energy level.…”