Spectral and surface investigations on Eu³⁺ doped K ₃Y(PO₄)₂ nanophosphor: A promising orange-red phosphor for white light-emitting diodes

Eu³⁺ doped K₃Y(PO₄)₂ nanophosphors have been synthesized by the combustion method and their spectral and surface properties were examined. The phosphors have been well characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and optical spectroscopy. For surface investigation X-ray photo electron spectroscopy has been used. Under various UV excitation (257, 320, 362, 382, 395 nm) the Eu³⁺ doped K₃Y(PO ₄)₂ phosphor emits characteristic (4f-4f) orange-red emission of the Eu³⁺ (⁵D₀ → ⁷F_j, j = 1, 2, 3, 4). The absorption spectra of the phosphor were found to be consistent with the excitation spectra. Diffuse reflectance spectra were used to calculate the band gap of 4.67 eV. The calculated International Commission on Illumination coordinates (0.628, 0.370) of the phosphor under an excitation wavelength of 395 nm was found to be similar to the commercially available Y₂O₂S:Eu³⁺ (0.622, 0.351). Therefore, the material may be a good candidate for the production of the red component in the UV chip based WLEDs.