The Yb3＋：LiGd（WO4）2 crystal with the dimension of Ф15×35 mm3 was grown by Czochralski technique. The spectroscopic characterization and fluorescence dynamics of Yb3＋ in yb3＋：LiGd（WO4）2 crystal were inve...The Yb3＋：LiGd（WO4）2 crystal with the dimension of Ф15×35 mm3 was grown by Czochralski technique. The spectroscopic characterization and fluorescence dynamics of Yb3＋ in yb3＋：LiGd（WO4）2 crystal were investigated. The yb3＋：LiGd（WO4）2 crystal exhibits a broad absorption band centered near 975 nm with the linewidths of 16 and 11 nm and maximal absorption cross-section of 3.60 × 10-20 and 2.90× 10-20 cm2 for π- and σ-polarization, respectively. The emission broadband has an FWHM of 47 and 45 nm with the emission cross sections of 3.92 × 10-20 and 3.34× 10-2o cm2 at 1020 nm for re- and or-polarization, respectively. The measured fluorescence lifetime is 398 gs. The blue light emission around 480 nm through cooperative upconversion from the de-excitation of excited Yb3＋-Yb3＋ pairs at 4 K was observed under 932-nm excitation and demonstrated.展开更多
Er3＋ doped potassium gadolinium molybdate （KGM） phosphor with sensitizer Yb3＋ ion was synthesized by the Pechini method using citric acid and ethylene glycol. The crystallization processes of the phosphor precurso...Er3＋ doped potassium gadolinium molybdate （KGM） phosphor with sensitizer Yb3＋ ion was synthesized by the Pechini method using citric acid and ethylene glycol. 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 ℃ for 5 h. 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 possible UL mechanisms of Er3＋ were explained by means of an energy level diagram. The maximum luminescent intensity was achieved when the concentration of Er3＋, Yb3＋ arrived at 1 mol.% and 20 mol.%, respectively.展开更多
基金Support by the National Natural Science Foundation of China(No.60808033)train object program of Jiangxi Province Young Scientists,Natural Science Foundation of Jiangxi Province(No.2011BAB206029,2010GQS0064 and 2008GZW0012)excellent young academic talent program of Jiangxi University of Finance and Economics
文摘The Yb3＋：LiGd（WO4）2 crystal with the dimension of Ф15×35 mm3 was grown by Czochralski technique. The spectroscopic characterization and fluorescence dynamics of Yb3＋ in yb3＋：LiGd（WO4）2 crystal were investigated. The yb3＋：LiGd（WO4）2 crystal exhibits a broad absorption band centered near 975 nm with the linewidths of 16 and 11 nm and maximal absorption cross-section of 3.60 × 10-20 and 2.90× 10-20 cm2 for π- and σ-polarization, respectively. The emission broadband has an FWHM of 47 and 45 nm with the emission cross sections of 3.92 × 10-20 and 3.34× 10-2o cm2 at 1020 nm for re- and or-polarization, respectively. The measured fluorescence lifetime is 398 gs. The blue light emission around 480 nm through cooperative upconversion from the de-excitation of excited Yb3＋-Yb3＋ pairs at 4 K was observed under 932-nm excitation and demonstrated.
基金Project supported by Shandong Province Natural Science Foundation (Y2008F10)the Award Fund for Prominent Youth Scientists of Shandong Province (2008BS09006)Shandong Province Higher Educational Science and Technology Program (J10LD1810-13)
文摘Er3＋ doped potassium gadolinium molybdate （KGM） phosphor with sensitizer Yb3＋ ion was synthesized by the Pechini method using citric acid and ethylene glycol. 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 ℃ for 5 h. 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 possible UL mechanisms of Er3＋ were explained by means of an energy level diagram. The maximum luminescent intensity was achieved when the concentration of Er3＋, Yb3＋ arrived at 1 mol.% and 20 mol.%, respectively.
