Preparation And Luminescent Properties Of Long Afterglow Materials Based On The Luminescent Center Of Mn

Long aftergrow phosphors has been widely used in commercial practical flat paneldisplay, such as emergency lighting, road signs, and shine glasses, ceramics, etc. In recentyears, the long aftergrow phosphors based on the luminescent center of Mn has been the focusdue to its cheap, low toxicity etc.In this paper, three kinds of long aftergrow phosphors have been developed. At first, ablue green long aftergrow phosphor MgAl₂O₄:Mn²⁺, Dy³⁺was synthezied by combustionmethod. The properties and phosphorescence mechanism were also studied detailedly with variousanalytical measures. When1.0%of MnCO3and0.12%H3BO3were used, and combused at700℃, the luminescence of MgAl₂O₄:Mn²⁺, Dy³⁺reach maximum. XRD experiments indicatedthat the type of phosphors was spinel. The PL spectrum was also investigated. Results showed thatboth MgAl₂O₄:Mn²⁺and MgAl₂O₄:Mn²⁺, Dy³⁺had a strong exitation wavelength at213nmand emission wavelength at492nm. Besides, MgAl₂O₄:Mn²⁺, Dy³⁺had another two emissionpeaks at518nm and525nm, which ascribed to4T1â†'6A1transition of Mn²⁺. Furthermore, theintensity of MgAl₂O₄:Mn²⁺was improved when Dy³⁺was doped, but the PL peaks did notchanged, indicating the codopant system exist Dy³⁺â†'Mn²⁺energy transfer.Secondly, Si⁴⁺and Mg²⁺doped red long aftergrow phosphors Zn₃（PO₄）₂:Mn²⁺wasdeveloped by solid-state reaction method. The properties and phosphorescence mechanism werealso carried detailedly. Results showed that without precombustion, the sample was doped with0.02mmol Si and annealed at900℃for three hours, the lifetime of phosphors could reach116s, and the relative intensity was272mcd/m2, while when0.01mmol Mg was doped, thelifetime of phosphors could reach118s, and the relative intensity was296mcd/m2.Thirdly, Zr⁴⁺and Mg²⁺doped red long aftergrow phosphors Zn₃（PO₄）₂:Mn²⁺weredeveloped by solid-state reaction method. When0.15%Mg²⁺and0.01%Zr⁴⁺were dopedrespectively, the lifetime reached the maximum of136s and125s.