Research On The Preparation And Luminescence Properties Of Galliate Red Phosphors,an Energy Saving And Environmental Material

Compared with the traditional incandescent lamps,fluorescent LED has many advantages,such as high efficiency,energy saving,environmental protection,long service life,small size and so on,so it is called the fourth generation lighting source.Unfortunately,both the efficient and reliable phosphors for plant LED lighting and indoor lighting are scarce,which limits the widespread use of LED to some extent.Therefore,it is of great significance to develop red phosphors with high efficiency and reliability.In this paper,Ca₁₄Zn₆Ga₁₀O₃₅:Mn⁴⁺ red phosphors and Ca₅Ga₆O₁₄:Eu³⁺ red phosphors were studied.The details are as follows:（1）Under optimum synthesis conditions,ZnO raw material was gradually replaced by the MgO raw material with different mole content to explore the effect of Mg²⁺ substitution of Zn²⁺ on the crystal structure and luminescence properties of red Ca₁₄Zn₆Ga₁₀O₃₅:Mn⁴⁺ phosphors.The results showed that appropriate Mg²⁺ partially replaced by Zn²⁺ is conducive to improving the luminous intensity and quantum efficiency of red phosphor powder.This is because,on the one hand,the addition of Mg²⁺ plays the role of cosolvent in the synthesis of red phosphor powder,making the synthesized red phosphor powder more uniform.On the other hand,the substitution of Mg²⁺ for Zn²⁺ leads to enhanced lattice rigidity and hence enhanced luminescence.（2）Ca₅Ga₆O₁₄:Eu³⁺ red phosphors were synthesized by high temperature solid state method at 1200℃ and 6 hours.The red phosphor can be excited by the narrow band of 280nm and the narrow band of 464nm.The red phosphor can emit the narrow-band red light located in 611nm.The emission spectra of the red phosphors with different Eu3 doping concentrations show that the optimum Eu³⁺ doping concentration is 0.07.With the increase of Eu³⁺ doping concentration,the fluorescence lifetime also increases.This anomalous phenomenon may be due to the fact that the substitution of Eu³⁺ for Ca²⁺ deepens the energy level trap.In addition,the red phosphor has good thermal stability and color purity.These results indicate that Ca₅Ga₆O₁₄:Eu³⁺ red phosphors have great application potential on white LED.