Spectroscopic behavior and Judd–Ofelt theoretical analysis of Eu 3+ activated Li 4 Zn(PO 4 ) 2 phosphor with red emission

A series of Li4Zn(PO4)2: Eu3+ excited red-emitting phosphors has been successfully synthesized by the Pechini sol-gel synthesis method. The phase purity, structural, and luminescence properties have been studied through X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR), and photoluminescence (PL) techniques. A strong band between 250 and 350 nm and some prominent peaks at 361, 382, 395, 465, and 525 nm were observed in the excitation spectra, which closely match the radiation of near-UV or blue light-emitting diode chips. The emission band centered at approximately 593 nm corresponds to the 5D0→7F1 magnetic-dipole transition, which gives rise to orange emission. The 5D0 –7F1 transition of Eu3+ occurs when stimulated by near-UV, blue, or even green light. In addition, the influence of doped Eu3+ content on the PL properties of the host material has been examined. The optimum emission intensity was found for 2.0 mol% concentration of Eu3+ ions; beyond this concentration, quenching was observed. The CIE chromaticity coordinates, color purity, and correlated color temperature (CCT) were calculated using the CIE chromaticity diagram. The chromaticity results demonstrate that the synthesized sample produces a strong red emission, indicating its suitability for use as a red component in white light-emitting diode (WLED) devices. Therefore, the overall findings suggest that the Li4Zn(PO4)2: Eu³+ phosphor exhibits promising optical and radiative characteristics, making it a potential candidate for application in WLED technology.