Synthesis And Photoluminescence Properties Of Three Novel Red Emission Nitride Phosphors

nitride phosphors,due to their high conversion efficiency,high physical-chemical stability,good thermal stability and broad emission colors,have received extensive attention as an important part for use in white LEDs in recent years.However,compared with tradition oxide phosphors,the research of nitrides is at an early stage,which still shows some disadvantages of poor species in nitride phosphors,complex synthesis production,high cost and lack of luminescence mechanism of nitride phosphors.In this paper,on the problems of the existing research on the nitride phosphors,three nitride phosphors were selected as luminescent materials and their structure information and luminescence properties are studied.The main works were contained as below:1.A novel red emitting nitride phosphors Li Sr₄?BN₂?₃:Eu²⁺ were obtained via solid state reaction at constant pressure at 800? and the structure information are studied by using structure refinement.The samples could efficiently excited by near ultraviolet chip and show a single intense broad emission band at 550-750 nm.Moreover,a nontypical emission blue-shift in the single luminescence center with increasing temperature luminescence properties is also investigated.2.Eu²⁺ doped Mg₃N₂ phosphors was synthesized by solid state reaction at 800? using the Mg as starting material.The excitation spectra of the Mg₃N₂:Eu²⁺ phosphors showed strong excitation in the range 250–450 nm and the PL spectra show a red emission under 400 nm excitation in the range 500–800 nm.3.Li Sr Al₃N₄:Eu²⁺ was synthesized using a solid-state reaction method.The resulting phosphors can eradiate a red emission band at about 650nm?FWHM = 50nm?under blue light?? = 470 nm?excitation.Its emission intensity at 150? remained 87.5% of that measured at room temperature.