Preparation and upconversion luminescence of nanocrystalline Gd2O3: Er3+, Yb3+

Nanocrystalline Gd1.77Yb0.2 Er0.03O3 samples were prepared by combustion and precipitation methods. Structures and upconversion luminescence properties of samples were studied. The results of XRD show that all samples are cubic structure, the average crystallite size could be calculated as 23 nm and 39 nm, respectively. The lattice constants were obtained. The FT-IR spectra were measured to investigate the vibrational feature of the samples. Upconversion luminescence spectra of samples under 980 nm laser excitation were investigated. The strong red emission of samples were observed, and attributed to F-4(9/2) -> I-4(15/2) transitions of Er3+ ions, the emission intensity for sample synthesized by precipitation method is stronger compared to that of combustion method. The possible upconversion luminescence mechanisms in nanocrystalline Gd1.77Yb0.2 Er0.03O3 were discussed.