Preparation And Luminescence Properties Of Red Emission Nitride Phosphor

With the properties of high luminous efficiency,low cost,flexible design of spectrum,pc-LEDs based solid state lighting（SSL）are replacing traditional incandescent and fluorescent lamps to be the next generation light source.The conventional w LEDs encounter low rendering index and high color temperature.It is important to search for efficient and excellent red fluorescent materials.Nitride phosphor have these merits,such as physical and chemical stability,outstanding thermal stability and abundant emission tailoring ascribed to structural diversity,these enables them to be one of the most suitable luminescence materials for SSL.The most conventional nitride phosphor such as M₂Si₅N₈:Eu²⁺and Ca Al Si N₃:Eu²⁺,their broad emission band largely limit the further improvement of luminous efficiency.The new generation nitride red Sr Li Ai₃N₄:Eu²⁺phosphor with the narrow band emission and excellent thermal quenching behavior.However,its application range is still hindered by its instability against moisture at ambient.For further enhancement of luminous efficiency,it is necessary to find novel nitride red phosphor with narrow band emission.The performance of white LED is largely dependent on the emission wavelength of phosphors,so it is of great significance to discovery novel phosphors with adjustable emission color.These main researches are as follows:（1）Sr Li Ai₃N₄:Eu²⁺phosphor was prepared at conventional pressure and its synthesis conditions,structure and luminescence properties were invesgated.The Sr Li Al₃N₄:Eu²⁺-Pi G was prepared through embedding the phosphor particles into Sn-P-F-O glass with low melting temperature,the obtained Sr Li Al₃N₄:Eu²⁺-Pi G sample kept 80%of its initial emission intensity after immerging in water for 96 hours,which indicates great improvement water resisting ability.（2）Novel red emission nitride Li₂Ca₂Mg₂Si₂N₆:Eu²⁺phosphor was synthesized under conventional pressure.Phosphor show emission at 638 nm and FWHM at 62 nm.The effect of Li₃N content and doped concentration on phase formation was studied as well as luminescent properties.Moreover,a warm white light was realized with rendering index of91 and color temperature of 4226 K.（3）Series of oxide phosphors,such as Ca₁₄Al₁₀Zn₆O₃₅:Bi³⁺,Sm³⁺,Gd Sr₂Al O₅:Tb³⁺,Eu³⁺,Sr₃Lu₂（BO₃）₄:Ce³⁺,Tb³⁺were prepared via high temperature solid-state method.The luminescence properties and energy transfer mechanism are studied in detail.The potential application on w LEDs were also evaluated.