Judd–Ofelt Intensity Parameters and Optical Properties of Eu/Li Co‐Doped CeO₂ Phosphor

In this work, the intense orange‐red emission of Eu 3+ singly and Eu 3+ /Li + co‐doped CeO 2 phosphors synthesized by solution combustion using urea as fuel was investigated experimentally and theoretycally. X‐ray diffraction and high‐resolution transmission electron microscope analysis confirmed the formation of a single‐phase CeO 2 cubic with high crystallinity. Under 360 nm excitation, the phosphors emitted an intense orange–red region of Eu 3+ as a function of Li + doping content. Significantly, it was enhanced 12/10 times by Li + co‐doping due to the increased crystallinity of the host lattice. The energy transfer proccesse associated with cross‐relaxation is responsible for decreasing the experimental lifetime of Eu 3+ . The influence of Li + doping content on the characterization properties of CeO 2 :Eu, Li phosphors was further explained using Judd‐Ofelt (J−O) theory, from which branching ratios ( β r ), transition probability ( A ), radiative lifetime ( τ cal ), and stimulated cross‐section ( σ e ) emission of the phosphors were estimated. The results indicate that an effectively improved crystallinity by Li + co‐doped CeO 2 :Eu can significantly enhance its luminescence intensity, making it suitable for optoelectronic and display applications.