Effects Of Substituting Matrix Elements In Feldspar Stucture Phosphors For White LEDs

In this thesis, a series of luminescence phosphors MAl₂Si₂O₈ : Eu²⁺ (M=Ca, Sr, Ba) were prepared via solid-state reaction in weak reductive atmosphere. And by means of researching the relationship between phase composition and crystal structure, and luminescence properties, the quantitative and half- quantitative relations between the composition, crystal structure and luminescence properties of Eu²⁺ activated alkaline earth aluminosilicate were obtained. The exploration of inherent law has provided scientific reference for obtaining high performance and white light-emitting materials.SrAl₂Si₂O₈:Eu²⁺ blue phosphor preparation conditions are optimized by orthogonal test, and the role of solvent for further study found a flux solvent and boric acid matrix components play a dual role of replacement. Eu²⁺ adopted MAl₂Si₂O₈ (M=Ca, Sr, Ba) phosphor were prepared by traditional solid state method. The lattice positions and the luminescent mechanism of Eu²⁺ in the host were discussed; the effects of Bâ…¢and Gaâ…¢-substitution on the host lattices and spectral properties were also investigated. It was found that when Bâ…¢and Gaâ…¢entered MAl₂Si₂O₈ lattice and substituted Alâ…¢, the lattice parameters (a, b, c) and unit cell volume of phosphors MAl₂Si₂O₈: Eu²⁺ decreased linearly and the luminescence spectra of these phosphors are blue shif with the increasing of the amount of Bâ…¢-substitution, but he lattice parameters (a, b, c) and unit cell volume of phosphors MAl₂Si₂O₈: Eu²⁺ increased linearly and the luminescence spectra of these phosphors are red shif as the increasing of the amount of Bâ…¢-substitution.The effects of Mn²⁺ concentration on the host lattices and spectral properties of Ca_0.755-xAl₂Si₂O₈: Eu²⁺, Mn²⁺x were also investigated.The intense white emitting phosphors Ca_0.755-xAl₂Si₂O₈: Eu²⁺, Mn²⁺x were synthesized. Color coordinates of the phosphor is (0.292913, 0.291844), color temperature: 8517K.