Electronic structure and photoluminescence properties of single component white emitting Sr3LuNa(PO4)3F:Eu2+,Mn2+ phosphor for WLEDs

Abstract

A series of single component Sr₃LuNa(PO₄)₃F:Eu²⁺,Mn²⁺ phosphors with tunable colours have been firstly obtained through solid state reactions. Structure optimization and electronic structure analysis of the host were performed by density functional theory using the CASTEP code. Sr₃LuNa(PO₄)₃F:Eu²⁺ phosphors can be efficiently excited by n-UV light and give bright blue emission with good colour purity. Utilizing the Eu²⁺ → Mn²⁺ energy transfer, the Mn²⁺ ion was well sensitized and single component Sr₃LuNa(PO₄)₃F:Eu²⁺,Mn²⁺ phosphors with tunable colours have been obtained successfully. The energy transfer mechanism was investigated by Dexter's energy transfer theory and the critical distance for the doped ions was calculated using the spectral overlap method. Moreover, by coating our prepared typical samples on 405 nm UV chips, white LED devices have been fabricated and the corresponding luminescence performance was studied. The investigation results on the properties of the as-prepared samples revealed that the Sr₃LuNa(PO₄)₃F:Eu²⁺,Mn²⁺ phosphors might have potential application in n-UV WLEDs.