Luminescent Properties of Ce Doped LuAG Thin Films Prepared by Pechini Sol-gel Method

Compared to phosphors, scintillating films are shown as a better feature for high-resolution display devices with low loss diffusion. Ce3+ doped lutetium aluminum garnet (Lu3Al5O12, LuAG) scintillating films with different Ce3+ concentrations have been fabricated by Pechini sol-gel processing combined with the spin-coating technique and characterized by X-ray diffraction (XRD) and photoluminescence (PL) under excitation of UV-VIS light. The results of XRD patterns indicate that the specimen under study is a well-crystallized single-phase of cubic structure. Under an excitation of 442nm, it is found that the PL spectra is the typical Ce3+ emissions located in the 460-650 nm consisting of two emission bands due to the transitions from the lowest 5d excited state (2D) to the 4f ground state of Ce3+, which matches well with the sensitivity curve of the Si-photodiode. The luminescent intensity of LuAG: Ce3+ films varies with the Ce3+ contents and reaches the maximum at 1.0 mol% doped. With the increase of calcining temperature, the luminescence intensity in the PL spectra of LuAG:Ce3+ films is found to increased accordingly due to the improved crystallization.