Fuzhong Gong

Photoluminescence properties of a novel phosphor CaB2O4:Eu3+ under NUV excitation

The new borate phosphor CaB(2)O(4):Eu(3+) was synthesized by solid-state method and their photoluminescence properties were investigated. The results show that the pure phase of CaB(2)O(4) could be available at 900 degrees C, CaB(2)O(4):Eu(3+) phosphor could be effectively excited by the near ultraviolet light (NUV) (392 nm), and the luminescent intensity of CaB(2)O(4):Eu(3+) phosphor reached to the highest when the doped-Eu(3+) content was 4 mol%. The emission spectra of CaB(2)O(4):Eu(3+) phosphor could exhibit red emission at 612 nm and orange emission at 588 nm, which are ascribed to the (5)D(0)-(7)F(2) and (5)D(0)-(7)F(1) transitions of Eu(3+) ions.

Synthesis and luminescence properties of the red phosphor CaZrO3:Eu3+ for white light-emitting diode application

Eu3+-doped CaZrO3 phosphor with perovskite-type structure was synthesized by the high temperature solid-state method. The samples were characterized by X-ray diffraction, scanning electron microscopy, fluorescence spectrophotometer and UV-vis spectrophotometer, respectively. XRD analysis showed that the formation of CaZrO3 was at the calcinations temperature of 1400°C. The average diameter of CaZrO3 with 4 mol% doped-Eu3+ was 2µm. The PL spectra demonstrated that CaZrO3:Eu3+ phosphor could be excited effectively in the near ultraviolet light region (397 nm) and emitted strong red-emission lines at 616 nm corresponding to the forced electric dipole 5D0 → 7F2 transitions of Eu3+. Meanwhile, the light-emitting diode was fabricated with the Ca0.96ZrO3:Eu0.043+ phosphor, which can efficiently absorb ∼ 400 nm irradiation and emit red light. Therefore Ca0.96ZrO3:Eu0.043+ may have applications for a near ultraviolet InGaN chip-based white light-emitting diode.

Synthesis and photoluminescence properties of MZr2(PO4)3:Eu3+; Bi3+ (M=Na; K) phosphors

A series of new red phosphors, MZr2(PO4)3:Eu3+; Bi3+ (M=Na; K), were synthesized using the solidstate reaction method, and their photoluminescence spectra were measured. The MZr2(PO4)3:Eu3+; Bi3+ (M=Na; K) phosphors were efficiently excited by an ultraviolet (UV; 395 nm) source, and showed intense orange-red emission at 595 nm. Further investigation of the concentration-dependent emission spectra indicated that the MZr2(PO4)3:Eu3+; Bi3+ (M=Na; K) phosphors exhibit the strongest luminescence intensity when y = 0.01 in NaZr2(0:95−y)(PO4)3:Eu0.103+, Bi2y3+ and y = 0.09 in NaZr2(0.95−y)(PO4)3:Eu0.103+, Bi2y3+, whereas the relative PL intensity decreases with increasing Bi3+ concentration due to concentration quenching. The addition of Bi3+ widens the excitation band of NaZr2(0.95−y)(PO4)3:Eu0.103+, Bi2y3+ around 320 nm, which provides the useful idea of broadening the excitation band around 300–350 nm to fit the ultraviolet chip.