Red light emitting BaNb2O6:Eu3+ phosphor for solid state lighting applications

Europium doped barium niobate (Eu3+:BaNb2O6) phosphors were successfully synthesized by conventional solid state reaction method. Thermogravimetric analysis-differential scanning calorimetry (TGA-DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterization techniques have been used to disclose thermal, structural and morphological properties of the synthesized phosphors. X-ray diffraction pattern for the synthesized phosphor calcined at 1200 degrees C confirms the formation of pure orthorhombic phase for BaNb2O6. In addition to the above mentioned characterizations, photoluminescence properties were also investigated for the BaNb2O6 phosphor under near-UV/blue excitations. Intense red emission observed at 611 nm due to D-5(0) -> F-7(2) transitions of Eu3+ under the excitations of both 394 nm (F-7(0) -> L-5(6)) and 466 nm (F-7(0) -> D-5(2)). The CIE chromaticity coordinates evaluated from the emission spectra are falling in the pure red region of the CIE 1931 diagram, which are very much close to the commercial red phosphor (Y2O2S:Eu3+). The above results indicate that Eu3+ doped BaNb2O6 phosphors may be potential candidates to use in white LEDs in which tricolor (red/green/blue) phosphors are excited by near ultraviolet light