Preparation and spectral characteristics of Ce3+-activated boroaluminate LaAl2B3O9

Ce3+-activated (1.0–10 mol%) aluminoborate LaAl2B3O9 was prepared via the chemical sol–gel method. The phosphors were characterized by X-ray diffraction and scanning electron microscopy measurements. The luminescence performances such as photoluminescence excitation and emission spectra, the thermal quenching, and the luminescence decay curves (lifetimes) were detected to the phosphors. The influences of Ce3+ activator concentration on the phase evolution and luminescence properties were investigated. Ce3+ ion has only one crystallographic site occupying on La3+ site in LaAl2B3O9 lattice, which results in the typical doublet blue emission band due to 4f65d → 4f7 transition. The 2FJ (J = 7/2, 5/2) energy gap of Ce3+ ions in this host is about 2,100 cm−1. In total, 7 mol% of Ce3+-doped LaAl2B3O9 exhibits the brightest blue luminescence color with CIE coordinates of (x = 0.149, y = 0.123) and an absolute quantum efficiency of 76.0 %. The thermal stability of the luminescence was evaluated by the temperature-dependent luminescence intensity. The luminescence of phosphor shows a good thermal quenching with a high activation energy of ΔE = 0.34 eV, indicating it could be used at operation temperature 100–150 °C.