Synthesis and up-conversion luminescence of Yb³⁺/Er³⁺/Tm³⁺ doped Ca₉Y(PO₄)₇

Abstract

Samples of Ca 9 Y(PO 4 ) 7 co-doped with Yb 3+ /Er 3+ , Yb 3+ /Tm 3+ , or Yb 3+ /Er 3+ /Tm 3+ have been synthesized through two different routes, i.e. a modified hydrothermal method, followed by annealing in air at 850 1C and a solid-state reaction. The results of SEM and TEM show that the particle size of the samples synthesized by the solid state reaction method is about several micrometers, while that of the sample synthesized by the modified hydrothermal method is around 180 nm. The up-conversion luminescence of samples is studied as a function of different Yb 3+ , Er 3+ , Tm 3+ ion concentrations and laser powers. Under 980 nm laser excitation, samples of Yb 3+ /Er 3+ co-doped Ca 9 Y(PO 4 ) 7 generate green and red emissions, while samples co-doped by Yb 3+ /Tm 3+ generate blue and red emissions. The red emission is most intense in Yb 3+ /Er 3+ co-doped samples, while blue emission is predominant in Yb 3+ /Tm 3+ co-doped samples. The main mechanism that allows for the up-conversion observed in Yb 3+ /Er 3+ , Yb 3+ /Tm 3+ or Yb 3+ /Er 3+ /Tm 3+ doped Ca 9 Y(PO 4 ) 7 is attributed to the energy transfer among Yb 3+ and the various Er 3+ /Tm 3+ ions in excited states.

Incommensurately modulated structure and spectroscopic properties of CaGd2(MoO4)4:Ho3+/Yb3+ phosphors for up-conversion applications

“…Rare earth bearing oxide crystals are the basic luminescent materials in modern photonics and laser technology because of high emission efficiency, thermal and chemical stability, and different spectroscopic properties that can be tuned by composition [1][2][3][4][5][6][7][8][9]. One of the most interesting effects observed in rare-earth-doped photoluminescence materials is the frequency conversion from near infrared radiation of low photon energy to visible high photon energy radiation or upconversion (UC) [10][11][12][13][14][15][16][17][18][19][20]. The UC materials have shown potential applications in various fields including noncontact and nondestructive temperature sensing, biomedical imaging and optical frequency conversion in photocatalytic composites [14,15,20,[21][22][23][24].…”

The influence of charge compensation defects on the spectroscopic properties of europium doped Ca9Y(PO4)7

“…7 One of the promising materials in phosphates family is Ca 9 Y(PO 4 ) 7 , which has two different cations (Ca 2+ and Y 3+ ) that are available for lanthanides substitution. [8][9][10][11] This material doped with Eu 2+ and Eu 3+ ions simultaneously consists of two components that are essential to achieve the emission of white light. Ca 9 Y(PO 4 ) 7 belongs to the whitlockite family and can be described by the general formula: Ca 9 R(PO 4 ) 7 , where R ¼ Ln, Pr, Eu, Tb, Dy, Ho, Er, Y, Bi, Al, Lu.…”