A Single-Phase Full-Color Ca4Si2O7F2:Ce3+, Tb3+, Sm3+ Micron Belt Mat for White-Light Emitting Diode Application

A new kind of Ca4Si2O7F2:Ce3+, Tb3+, Sm3+ oxyfluoride phosphor micron belt mat was obatained by simply electrospinning process and subsequent heat treatment. XRD result shows that a pure Ca4Si2O7F2 phase can be obtained at low temperature of around 900 °C. The micron belt precursor has a smooth surface and uniform morphology, and the width and thickness of the belt is about 2 μm and 200 nm. The morphology of micron belt is well retained after heat treatment, forming a plat phosphor mat consisting of uniform micron belt network. Ca4Si2O7F2:Ce3+, Ca4Si2O7F2:Tb3+, and Ca4Si2O7F2:Sm3+ exhibit the characteristic emissions of Ce3+ (4f7→4f65d1, blue), Tb3+ (4f8→4f75d, green), and Sm3+ (4f6→4f65d, red) under the excitation of near-UV light, respectively. By adjusting the doping concentration of Ce3+, Tb3+, Sm3+ ions a white emission in a single phase was obtained under the excitation of 360 nm. We have demonstrated that Ca4Si2O7F2:Ce3+, Tb3+, Sm3+ phosphor mat can be a promising candidate for a color-tunable phosphor mat applied in a near-UV White light emitting diodes.