Preparation of Gd_2O_3:Yb,Er and Gd_2O_2S:Yb,Er infrared-to-visible conversion phosphor ultrafine particles using an emulsion liquid membrane system

摘要

Upconvetring phosphor fine particles (Gd_2O_3:Yb,Er and Gd_2O_2S:Yb,Er) have been prepared,using an emulsion liquid membrane (ELM,water-in-oil-in-water (W/O/W) emulsion) system.The composite Gd-Yb-Er oxalate particles obtained in the ELM system were mainly 20-60 nm in size,together with a smaller amount of submicrometer-sized spherical particles.Nanometer-sized Gd_2O_3:Yb,Er and Gd_2O_2S:Yb,Er particles were obtained by calcination in air and in sulfur atmosphere,respectively,of the precursor oxalate particles prepared in the ELM system.Upconversion emissions(red and green) were obtained from the Gd_2O_3:Yb,Er and Gd_2O_2S:Yb,Er particles prepared in the ELM system under infrared exicitation (lambda_(ex)=980 nm) via a two-photon process.Upconversion phophor fine particles,about 50 nm in diameter,may be applied to the luminescent reporter material for the detection of the targeted andlyste in immunoassays or DNA assays.