Combustion synthesis and luminescence of monoclinic Gd2O3: Bi phosphors

Monoclinic Gd2O3: Bi phosphors were prepared with a combustion method at an ignition temperature as low as 240-300 °C using glycine as a fuel and PEG4000 as a dispersant. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy and transmission electron microscope. XRD indicated that both monoclinic and cubic Gd2O3: Bi3+ phosphors could be achieved with the combustion method by adjusting the molar ratios of glycine to NO3− (G/N). Blue (430-500 nm) emissions were observed with monoclinic Gd2O3: Bi3+ when excited with UV light in a wide spectrum range of 300-380 nm. Its PL intensity could be improved by calcining at a higher temperature or adding appropriate amount of PEG4000. TEM images show that the product consists of aggregate of nanospheres with 50-200 nm in size. Both excitation and emission spectrum of monoclinic Gd2O3: Bi phosphors match the requirement of light-conversion agent, and has a promising prospect in agriculture applications.