Photoluminescence investigations of (Y1− x Ln x )3Al5O12:Ce (Ln3+=Gd3+, La3+) nanophosphors

Abstract: (Y1− x Ln x )3Al5O12:Ce (Ln3+=Gd3+, La3+) phosphors were synthesized by in situ esterification. The effects of Gd3+ and La3+ ions on structure and luminescence of YAG:Ce were investigated. For Gd3+-doped YAG:Ce, when doping concentration increased beyond 50mol%, GdAlO3 phase appeared. For La3+-doped YAG:Ce, as doping concentration increased beyond 20mol%, YAG phase completely disappeared and LaAlO3 phase emerged. As the doping concentration of Gd3+ and La3+ increased, the maximum emission band showed red shift. Because radii of Gd3+ and La3+ were larger than that of Y3+, Gd3+ and La3+ replacement distorted YAG structure. More defects are formed in (Y1− x Ln x )3Al5O12:Ce, which acts as quenching center. Therefore, emission intensity of (Y1− x Ln x )3Al5O12:Ce was lower than YAG:Ce and luminescent lifetime of (Y1− x Ln x )3Al5O12:Ce was shorter than YAG:Ce. [Copyright &y& Elsevier]