Abstract: Gd2O2S:Yb3+,Er3+ nanopowders were fabricated by hydrothermal method assisting with reduction route utilizing commercially available reagents of Gd2O3,Yb2O3,Er2O3,HNO3,CO (NH2)2and C12 H25 SO4Na.The structure,morphology and up-conversion luminescent properties were characterized by fourier transform infrared spectroscopy (FT-IR),X-ray diffractometry (XRD),transmission electron microscopy (TEM),selected area electron diffraction (SAED) and up-conversion luminescence spectra (UPL).The results show that the molar ratio of Gd3 + ∶ CO(NH2) 2∶ SO42-=2∶1∶ x have a significant influence on the structure of the as prepared products.The precursor synthesized with x =1.0 could be converted into pure Gd2O2S phase by calcining at 800 ℃ for 2 h in the hybrid atmosphere of flowing hydrogen and argon (90; Ar + 10; H2) resulting in quasi-spherical and agglomerated morphology with 30 nm in size.Under 980 nm infrared light excitation,UPL spectra of the Gd2O2S∶Yb3+,Er3+ nanophosphors show a red emission at 671 nm as the most prominent peak and a green emission at 548 nm as the secondary emission peak,which attribute to the 4F9/2→4I15/2 and 4S3/2→4I15/2 transitions of Er3 + ions.The quenching concentration of Er3+ ions is 5;,and the emission mechanism is two photo model.

Key words: Gd2O2S:Yb3+,Er3+ nanopowders were fabricated by hydrothermal method assisting with reduction route utilizing commercially available reagents of Gd2O3,Yb2O3,Er2O3,HNO3,CO (NH2)2and C12 H25 SO4Na.The structure,morphology and up-conversion luminescent properties were characterized by fourier transform infrared spectroscopy (FT-IR),X-ray diffractometry (XRD),transmission electron microscopy (TEM),selected area electron diffraction (SAED) and up-conversion luminescence spectra (UPL).The results show that the molar ratio of Gd3 + ∶ CO(NH2) 2∶ SO42-=2∶1∶ x have a significant influence on the structure of the as prepared products.The precursor synthesized with x =1.0 could be converted into pure Gd2O2S phase by calcining at 800 ℃ for 2 h in the hybrid atmosphere of flowing hydrogen and argon (90; Ar + 10; H2) resulting in quasi-spherical and agglomerated morphology with 30 nm in size.Under 980 nm infrared light excitation,UPL spectra of the Gd2O2S∶Yb3+,Er3+ nanophosphors show a red emission at 671 nm as the most prominent peak and a green emission at 548 nm as the secondary emission peak,which attribute to the 4F9/2→4I15/2 and 4S3/2→4I15/2 transitions of Er3 + ions.The quenching concentration of Er3+ ions is 5;,and the emission mechanism is two photo model.