Investigation On Luminescence Properties Of Ag Nanoparticles And Rare-earth Ions Codoped Glasses

Metal nanoparticles (Ag, Au) doped glass composites have extensive applications in opticaldevices such as optical storage, all-optical switch and optical transmission. The characterization ofmetal nanoparticles (NPs) doped glass has attracted intensive attention for their superior opticalproperties. Recently, many researchers have founded that the luminescence efficiency of rare-earth(RE) ions can be greatly improved when doped with metal NPs in the glass matrix. Here, rare-earthions doped bismuth glasses containing Ag NPs were synthesized by a chemical reduction method，which was based on the conventional high temperature melting-quenching technique. Theinfluences of Ag NPs on the visible, near-infrared and middle-infrared spectral characteristics wereparticularly investigated. And the mechanisms of energy transfer and luminescence of RE ionsdoped glasses were analyzed.In chapter one, the concept of glasses and RE ions’ luminescence, the main characteristics ofmetal NPs, and preparation methods of the glasses doped with RE ions and metal NPs weresummarized. The research progresses of RE ions doped glasses containing Ag NPs wereintroduced. Also the significance and main content of the research were summed up.In chapter two, the theoretical backgrounds such as Judd-Ofelt theory, McCumber theory,Futchbauer-Ladenburg theory, multi-phonon non-radiative relaxation probability and energytransfer theory were introduced in detail.In chapter three, the methods of measurement and preparation of these glasses were presented.In chapter four, effects of Ag NPs on the1.54μm near-infrared luminescence properties of the60Bi2O3-35B2O3-5TiO2glasses were mainly studied. And the influence of Ag NPs over surfaceplasmon resonance (SPR) and fluorescence spectra were discussed. Further, the mechanism ofluminescence enhancement which was caused by Ag NPs was also analyzed. The results show that1.54μm fluorescence intensity first increases with the increasing AgCl concentrations. The1.54μm fluorescence intensity of thesample containing0.2wt%AgCl reaches a maximum value.In chapter five, luminescence properties of Ag NPs and Tm3+ions codoped53.3BiO1.5-33.3GeO2-13.4NaO0.5glasses were studied. On474nm excitation, obvious enhancement of Tm3+ions emission was observed. Besides, a broad emission band, which was centered at568nm, wasalso enhanced. That was owing to the Ag NPs. The luminescence mechanism and the mainprocedure of energy transfer between RE ions were investigated.In chapter six, the luminescence properties of Tm3+/Ho3+co-doped53.3BiO1.5-33.3GeO2-13.4NaO0.5glass at2.0μm were studied. The effect of Ag NPs concentrations and SPRon the2.0μm luminescence was analyzed. Results show that2.0μm fluorescence intensity of Ho3+reaches a maximum value, which is ten times larger than those without AgCl. The process of energy transfer between Tm3+ions and Ho3+ions was discussed. Also the luminescencemechanism was investigated.Finally, the main conclusions of this research were briefly summarized, and someimprovements which should be done in the future work are also discussed.