A series of Eu³⁺or Tb³⁺doped Ba₂Ca(BO₃)₂phosphors were synthesized by a high temperature solid state method, and the luminescence properties are investigated. Ba₂Ca(BO₃)₂:Tb³⁺can show an obvious green emission, and the peak locates at 551 nm, which corresponds to the ⁵D₄→⁷F₅transition of Tb³⁺. Ba₂Ca(BO₃)₂:Eu³⁺can present the characteristic emission of Eu³⁺, and the peak locates at 600 nm, which is ascribed to the 5D0→7F2 transition of Eu3+. In order to achieve the emission-tunable phosphors, the Eu³⁺/Tb³⁺co-doped Ba₂Ca(BO₃)₂are synthesized. When tuning the Eu³⁺or Tb³⁺concentration, Ba₂Ca(BO₃)₂:Eu³⁺, Tb³⁺can both show the tunable emission, which may be induced by the energy transfer from Tb³⁺to Eu³⁺.

For enhancing the emission intensity and broadening the excitation region of Ba₃Eu(PO₄)₃(BEP), Sm³⁺is doped as sensitizer in this paper. BEP:Sm³⁺can produce an obvious red emission at near ultraviolet (n-UV) radiation. An effective energy transfer from Sm³⁺to Eu³⁺is proved. The commission international de I’Eclairage (CIE) chromaticity coordinates of BEP:Sm³⁺locate at red region. When the environment temperature is 150 °C, the emission intensity of BEP:0.10Sm³⁺is decreased to 76% of the initial one at room temperature, and the activation energy is calculated to be 0.164 eV, which can prove the good thermal stability of BEP:Sm³⁺. The results indicate that BEP:Sm³⁺may have potential applications in white light emitting diodes (LEDs).

Blue emitting phosphor SrZn₂(PO₄)₂:Eu²⁺ is synthesized by a high temperature solid state method, and the luminescent properties are investigated. At the 330 nm radiation excitation, SrZn₂(PO₄)₂:Eu²⁺ presents an emission band at 416 nm, which is assigned to the 4f⁶5d¹→4f⁷ transition of Eu²⁺ion. The concentration quenching effect of Eu²⁺in SrZn₂(PO₄)₂has been validated and proved to be a resonant type via a dipole-dipole interaction. The critical distance (R_c) of Eu²⁺in SrZn₂(PO₄)₂is calculated to be 3.244 nm. The Commission International de I’Eclairage (CIE) chromaticity coordinates of SrZn₂(PO₄)₂:Eu²⁺ locate at the blue region, such as (0.150, 0.072). The results indicate that the SrZn₂(PO₄)₂:Eu²⁺ phosphor may have potential applications in white light emitting diodes (LEDs).

SrZn₂(PO₄)₂:Sm³⁺phosphor was synthesized by a high temperature solid-state reaction in atmosphere. SrZn₂(PO₄)₂:Sm³⁺phosphor is efficiently excited by ultraviolet (UV) and blue light, and the emission peaks are assigned to the transitions of ⁴G_5/2-⁶H_5/2(563 nm), ⁴G_5/2-⁶H_7/2(597 nm and 605 nm) and ⁴G_5/2-^{6H_9/2(644 nm and 653 nm). The emission intensities of SrZn₂(PO₄)₂:Sm3+are influenced by Sm3+concentration, and the concentration quenching effect of SrZn₂(PO₄)₂:Sm3+is also observed. When doping A+(A=Li, Na and K) ions, the emission intensity of SrZn₂(PO₄)₂:Sm3+can be obviously enhanced. The Commission Internationale de l'Eclairage (CIE) color coordinates of SrZn₂(PO₄)₂:Sm3+locate in the orange-red region. The results indicate that the phosphor has a potential application in white light emitting diodes (LEDs).}

A white emitting phosphor of YAl₃(BO₃)₄:Ce³⁺, Dy³⁺is synthesized by a solid state reaction, and its luminescent properties are investigated. Its phase formation is carried out with X-ray powder diffraction analysis, and there is no crystalline phase other than YAl₃(BO₃)₄. YAl₃(BO₃)₄:Ce³⁺can produce 422 nm blue emission under 367 nm excitation. The emission spectrum of YAl₃(BO₃)₄:Dy³⁺shows several emission peaks under 350 nm excitation, and the peaks locate at 485 nm, 575 nm and 668 nm, respectively. Emission intensities of Ce³⁺and Dy³⁺in YAl₃(BO₃)₄are influenced by their concentrations, and the concentration quenching effect is observed. Energy transfer from Ce³⁺to Dy³⁺in YAl₃(BO₃)₄is validated and proved to be a resonant type via a quadrupole-quadrupole interaction, and the emission color can be tuned from blue to white by tuning the ratio of Ce³⁺/Dy³⁺. Moreover, the critical distance (Rc) of Ce³⁺to Dy³⁺in YAl₃(BO₃)₄is calculated to be 1.904 nm.

A series of Ce³⁺, Eu²⁺and Ce³⁺-Eu²⁺doped Ca₉Al(PO₄)₇phosphors are synthesized by a high temperature solid-state method. Under 291 nm excitation, Ca₉Al(PO₄)₇:Ce³⁺has one emission band at 356 nm, which is attributed to 4f05d1→4f1 transition of Ce³⁺. Under 305 nm excitation, Ca₉Al(PO₄)₇:Eu²⁺presents one emission band at 445 nm, which is assigned to 4f 65d1→4f 7 transition of Eu²⁺. Energy transfer from Ce³⁺to Eu²⁺in Ca₉Al(PO₄)₇is validated and proved to be a resonant type via a quadrupole-quadrupole interaction. Critical distance (Rc) of Ce³⁺to Eu²⁺in Ca₉Al(PO₄)₇is calculated to be 1.264 nm. Moreover, the emission intensity of Ca₉Al(PO₄)₇:Ce³⁺, Eu²⁺can be tuned by properly adjusting the relative doping composition of Ce³⁺/Eu²⁺.

A series of Tb³⁺doped NaY(MoO₄)₂are synthesized by a solid-state reaction at 550 °C for 4 h, and their luminescent properties are investigated. The phase formation is carried out with X-ray powder diffraction analysis, and there is no other crystalline phase except NaY(MoO₄)₂. NaY(MoO₄)₂:Tb³⁺can produce the green emission under 290 nm radiation excitation, and the luminescence emission peak at 545 nm corresponds to the ⁵D₄→⁷F₅ transition of Tb³⁺. The emission intensity of Tb³⁺in NaY(MoO₄)₂is enhanced with the increase of Tb³⁺concentration, and there is no concentration quenching effect. The phenomena are proved by the decay curves of Tb³⁺. Moreover, the Commission International de I’Eclairage (CIE) chromaticity coordinates of NaY(MoO₄)₂:Tb³⁺locate in the green region.

A series of Sr₃Y(PO₄)₃:Eu₂₊samples are synthesized by the high temperature solid-state method. Sr₃Y(PO₄)₃:Eu₂₊shows an asymmetrical emission band under excitation of 350 nm. The emission peaks at 426 nm and 497 nm are assigned to the nine-coordination Eu₂₊and six-coordination Eu₂₊, respectively. The effects of Eu₂₊ doping content on the emission intensity and color are observed, and the concentration quenching effect is also observed. For two different Eu₂₊luminescence centers, the quenching mechanisms are dipole-dipole interaction and quadrupole-quadrupole interaction, respectively. And the critical distance of energy transfer is calculated by concentration quenching and turns out to be about 3.67 nm. The results above show that the asymmetrical emission band of Sr₃Y(PO₄)₃:Eu₂₊ comes from two different Eu2+₂₊ luminescence centers in the lattice.

A novel white-bluish emitting phosphor of Ba_0.49Sr_0.49)_2-B₂P₂O₁₀:0.02Eu²⁺is synthesized by the solid state reaction. Ba_0.49Sr_0.49)_2-B₂P₂O₁₀:0.02Eu²⁺can be effectively excited by 370 nm ultraviolet (UV) light, and exhibits two emission bands at 430 nm and 522 nm which are attributed to the d-f transitions of the Eu2+ ions in two different cation sites in the host lattices. And the chromaticity coordinate of Ba_0.49Sr_0.49)_2-B₂P₂O₁₀:0.02Eu²⁺phosphor is (0.29, 0.25).

A series of Ce³⁺ , Tb³⁺ or Ce³⁺ /Tb³⁺ doped YAl₃(BO₃)₄ phosphors are synthesized by a high temperature solid-state reaction, and their luminescent properties are investigated. YAl₃(BO₃)₄:Ce³⁺ shows a broad emission band at 422 nm under the 367 nm radiation excitation. YAl₃(BO₃)₄:Tb³⁺ can be efficiently excited by the ultraviolet (UV) light, and produces green emission. The emission intensity of YAl₃(BO₃)₄:Tb³⁺ can be enhanced by adjusting Tb³⁺ doped content, and reaches the maximum at 0.06 mol Tb³⁺. When Ce³⁺ is codoped, the emission intensity of Tb3+ in YAl₃(BO₃)₄ can be enhanced, but the commission international del’eclairage (CIE) chromaticity coordinates of YAl₃(BO₃)₄:Tb³⁺ have almost no change. Moreover, the energy transfer from Ce³⁺ to Tb³⁺ in YAl₃(BO₃)₄ is studied.