Synthesis and Luminescence Investigation of Eu3+ Doped Ca2KZn2V3O12 Phosphors: A Potential Material for WLEDs Applications

A series of white light emitting Ca 2 KZn 2–x V 3 O 12 :xEu 3+ ( x = 0.1, 0.2, 0.3, 0.4 and 0.5) phosphor samples were successfully synthesized by the traditional solid-state reaction method. The powder X-ray diffraction (XRD) patterns of the as-prepared sample reveal the high degree of crystallinity of the cubical structure with I a 3 ¯ d space group and without any other phase formation. Fourier transform infrared (FTIR) spectra confirmed the occurrence of characteristic vibrational bands of garnet vanadate. The optical diffuse reflectance spectra consisting of broad band absorption in the ultraviolet (UV) region and the sharp absorption in the visible region were ascribing to the charge transfer between ligand–metal in the VO 4 tetrahedral group and Eu 3+ ions. Under the UV and near-UV excitation wavelengths, the broad band emission and the sharp emission were ascribing to the host material charge transfer of the VO 4 tetrahedral group and f-f transitions of the rare-earth Eu 3+ ions respectively. Ultimately, through the doping concentration optimization, a high Color Rendering Index (CRI) and excellent Correlated Color Temperature (CCT) were achieved with cool white emission. Therefore, the contribution of Ca 2 KZn 1.8 Eu 0.2 V 3 O 12 phosphor was significant to phosphor-converted white light emitting device (WLEDs) excited with near ultraviolet.