Study On The Synthesis And Spectrum Properties Of Ce³⁺ Doped YVO₄ Phosphor

With the development of semiconductor technology,the luminescence efficiency of light-emitting diode(LED) has received gread improvement since it was invented in 1960s.Previously,the emission wavelength lied in red region,and up to now widens to cover the area from infrared region to the near ultraviolet region.Since white LED was fabricated from blue GaN LED chip and yellow light phosphor (Y3Al5O12:Ce³⁺,YAG) in 1996,it has been considered as a mainstream of the new light resource in 21st century for its low energy consumption and environmental friendship.The research of the white LED and phosphors is a type of significant work. Most commercial White LED is in the manner of light conversion, which is fabricated by coating YAG phosphors on the chip of blue LED. The YAG phosphors emit yellow light excited by the blue light and the two lights mix into white light. In this thesis, the synthesis and properties of Ce³⁺: YVO4phosphor is studied.In this work, several methods of synthesizing phosphors are introduced, and the Ce³⁺:YVO4 phosphor is synthesized by solid-state reaction in reductive atmosphere. XRD pattern shows that the structure of the phosphor is tetragonal which is formed under the sintering of 1100℃. The excitation spectra of Ce³⁺:YVO4 phosphor have two peaks, the major one is around 232nm which is attributed to the 4f-5d transitions of Ce³⁺ ions. The emission band is quitely wide , ranged blue light region and with a center at 424nm. Experimental results shows that the concentration of Ce³⁺ ions effects the luminescent properties of Ce³⁺:YVO4 phosphor. In this thesis, the best concentration of Ce³⁺ is optimized by comparing the luminescent intensities of YVO4 phosphors with different Ce³⁺ concentrations.