Chemical combustion synthesis and up-conversion properties of Er3+ doped Yb3Al5O12 powder

Er3+ doped Yb3Al5O12 powder has been prepared by chemical combustion and their structural and optical properties are determined by X-ray diffraction (XRD), transmission electron microscopy (TEM), and up-conversion (UC) spectra. XRD and TEM show that the powder is composed of a highly crystalline garnet phase. When excited by a 980 nm laser diode, the Er3+ doped Yb3Al5O12 powder shows an intense red UC fluorescent band that can be assigned to the transition 4F9/2 → 4I15/2 of Er3+ and a relatively weak green one corresponding to 2H11/2/4S3/2 → 4I15/2 in the UC spectra. The intensity ratio of the red to green emission is enhanced due to Li+ incorporation. This can be attributed to the modification of local crystal fields around the rare-earth ions. Our results suggest that rare-earth doped alumina nanomaterials have potential applications in flat-panel displays and multicolor fluorescent labels.