Upconversion luminescence of KGd(MoO4)2: Er3+,Yb3+ powder prepared by the Pechini method

摘要

Er3+doped potassium gadolinium molybdate (KGM) phosphor with sensitizer Yb3+ion has been synthesized by the Pechini method using citric acid and enthyleneglycol. The crystallization processes of the phosphor precursors were characterized by X-ray diffraction (XRD) and thermogravimetry-differential scanning calorimetry (TG-DSC), which indicated that ultrafine uniform crystallites of KGM:Er,Yb were obtained by sintering the precursors at above 650°C for 5h. Upconversion luminescence (UL) spectra of the samples were studied by a 976 nm semiconductor laser diode (LD) excitation. The UL spectra exhibited the green and red emission bands that were attributed to the 2H11/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+, respectively. The occurence of UL can be attributed to a two-photon process. The maximum luminescent intensity was achieved when the concentration of Er3+, Yb3+arrived at 1 mol% and 20 mol%, respectively.