Yanwen Tian

A Red-Emitting Phosphor and its Luminescent Properties

Under 616 nm monitoring, excitation peaks at 395, 465, and 535 nm were observed for the red-emitting phosphor Li0.3Y0.82Mo0.1W0.9O4+δ:0.08Eu3+ (LYMW), which was synthesized using the solid-state method. Particularly in the range of 250 to 420 nm, excited peaks can be assigned to the transitions of O2−→Mo6+/W6+/Eu3+ and four sharp peaks can be assigned to the 4f–4f transition of Eu3+ (∼360 nm from the 7F0→5D4 transition, ∼380 nm from the 7F0→5L7 transition, ∼395 nm from the 7F0→5L6 transition, and ∼415 nm from the 7F0→5D3 transition).

Structure and Luminescence Properties of New Green-Emitting Phosphor BaAl12O19:Tb

New green-emitting BaAl12O19:Tb phosphors were prepared by using the sol–gel method, and their structure and luminescence property were characterized by X-ray diffraction (XRD) analysis and fluorescence spectrometry. The results of XRD analysis revealed that a Ba1-xAl12O19:Tbx crystal structure was obtained at 1300 °C and Tb3+ ions substituted Ba2+ ions into the BaAl12O19 phase in the ion range x=0.005–0.05. The excitation peak of BaAl12O19:Tb was a wide band at approximately 240 nm, originating from the 4 f8–4 f75d1 transition of Tb3+. The emission spectrum consisted of eight emission peaks, originating from the 5D3–7Fi (i=6,5,4,3) and 5D4–7Fj ( j=6,5,4,3) transitions of Tb3+. The emission intensity of BaAl12O19:Tb phosphors at 543 nm was strongest when the phosphors were crystallized at 1300 °C for 2 h, and the content of Tb3+ was 2 mol %.

Preparation of Eu3+-Y3+ Coactivating Na+ Based Red-Emitting Luminous Materials for Light-Emitting Diodes and Investigation of Its Characteristics

By solid-state reaction and doping, a series of red-emitting phosphors NaxY0.92–x/3(MoO4)y(WO4)1–yO0.5 : zEu3+ have been synthesized. Through optimization of the process conditions and photoluminescent analysis, one type of red emission is obtained that matches nicely with ultraviolet light-emitting diode (UV-LED) chips.