Synthesis of Red-Emitting Ca3-xEuxZrSi2O9 Phosphors

Crystal structure and photoluminescent property of Eu3+-doped K3GdSi2O7

“…For the phosphors with x > 0.9, the relative emission intensity decreased compared to that of K 3 Gd 0.1 Eu 0.9 Si 2 O 7 (x = 0.9) due to the concentration quenching. This result indicates that the concentration quenching was not observed even by introducing a high amount of Eu 3+ ions (x = 0.9), whose concentration is considerably higher than those of the previous phosphors, such as Na 3 (Gd 0.98 Eu 0.02 )Si 2 O 7 [9], Sr(Gd 0.92 Eu 0.08 )Ga 3 O 7 [10], and Ca 2.83 Eu 0.17 ZrSi 2 O 9 [11]. This suppression of the concentration quenching is attributed that each Eu 3+ ion was satisfactorily separated in the lattice.…”

Luminescent Properties of Sr4Si3O8Cl4:Eu2+, Bi3+ Phosphors for Near UV InGaN-Based Light-Emitting-Diodes

“…When the energy transfer occurs between the same sites of activators, the intensity of multipole interaction can be determined by the change of the emission intensity from the emitting level. According to the report of Van Uitert [17], the emission intensity (I) of per activator ion follows the equation [18,19]: where I is the emission intensity, χ is the Eu 2+ concentration, K and β are constants for the same excitation condition for a given host crystal. Q is a constant of multipole interaction equals to 3, 6, 8 or 10 for energy transfer among the nearest-neighbor ions, dipole-dipole (d-d), dipole-quadruple (d-q) or quadruple-quadruple (q-q) interaction, respectively.…”

Enhanced luminescent properties of Ca3−Tb ZrSi2O9+/2 phosphors by Al3+ doping into the Zr4+ site in the host lattice

“…It is well known that alkaline-earth zirconium silicate phosphors exhibit good luminescent efficiency due to their outstanding optical properties coupled with photothermal stability and low thermal conductivity [4][5][6][7]. Furthermore, we have previously reported that red-emitting phosphors based on monoclinic Ca 3 ZrSi 2 O 9 can show good luminescence properties due to its layered structure [8], in which the CaO n (n¼6 and 8) polyhedron and ZrO 6 octahedron layers are separated by SiO 4 tetrahedron layers in the direction of the c axis [9][10][11][12]. In a layered structure, it is well known that energy transfer from one excited luminescent ion to another across the anion groups is inhibited by the long distance between cations.…”

“…In a layered structure, it is well known that energy transfer from one excited luminescent ion to another across the anion groups is inhibited by the long distance between cations. Therefore, phosphors based on layered structure should be resistant to concentration quenching, even if a large amount of activator is introduced into the host lattice [8,[13][14][15][16][17][18][19][20]. In addition, silicate materials have high thermal and chemical stabilities, low cost, and excellent waterresistance [21][22][23].…”