Study On The Luminescent Mechanism Of Silver Nano-particles Enhanced Rare Earth Doped Heavy Metal Glass

Rare earth ions doped heavy metal oxide glass has been widely used in laser,fiber amplifier,fiber communication,display and wide band gap solar cell.Bismuth and tellurite glasses are typical heavy metal oxide glasses.Bismuth glass and tellurite glass have excellent physical and chemical properties,such as excellent infrared transmittance,high refractive index,high density,good thermal stability and low phonon energy.They are good rare earth ion doped matrix materials.The significant enhancements of Tm³⁺:1.47 μm fluorescence intensity in silver nanoparticles embedded bismuth glass is observed.A series of glass system with the composition of 60Bi2O3-20 Si O2-20Ga2O3-1Tm2O3-x Ag NO3（where x=0.0,0.1,0.5,1.0,1.2,1.5,1.7 and 2.0 mol%）were prepared by the melt-quenching method technology.X-ray diffraction patterns show the amorphous properties of glass samples.Transmission electron microscopy images confirm the homogeneous dispersion of silver nanoparticles with average diameter 7.5 nm in glass.According to the absorption spectra,the local surface plasmon resonance band locates around 477-570 nm and shifts towards the longer wavelength with the increasing silver concentration.Under excitation of 800 nm laser diode,the 1.47 μm emission intensity undergoes significant enhancements by as much as 6 times,which is mainly attributed to the intensified local electric field of silver nanoparticles.Large magnitude of full-width at half-maximum,emission cross section,figure of merit of the 1.47 μm emission are calculated to be 128 nm,4.8×10-21 cm2 and 6.14×10-26 cm3,respectively.These results indicate that the materia is a promising gain medium for S-band optical amplifiers.Wide band gap solar cells for solar energy conversion are green and renewable energy sources.However,wide band gap solar cells have low photovoltaic conversion efficiency.It is one of the effective ways to improve the efficiency of solar photovoltaic conversion to convert the photons that can not be absorbed into the photons that can be absorbed by wavelength conversion.A series of glass samples with the composition of（69-x）Te O2-20B2O3-10 Zn O-1Er2O3-x Ag（where x=0.0,0.25,0.5,1.0mol%）were prepared by the melt-quenching method technology.The optical characteristics of tellurite glasses were recorded by optical absorption spectroscopy and fluorescence spectrophotometer.The down conversion emissions of Er³⁺ were characterized by exciting the glasses with excitation wavelength of 358 nm,366 nm and 379 nm,respectively.The up-conversion emissions of Er³⁺ were characterized at 980 nm excitation wavelength.The emissions spectra show interation of the sliver nanoparticles and Er³⁺.Compared with Er³⁺ doped samples without sliver nanoparticles,the intensities of Er³⁺ down conversion emissions intensity of containing 0.5 mol% sliver nanoparticles were enhanced up to 60%（excitation wavelength 358 nm）,40%（excitation wavelength 366 nm）and 27%（excitation wavelength 379 nm）,respectively.The intensity of up-conversion emissions at 532,554 and 671 nm are enhanced approximately 125%,250% and 166% times for the glasses with 0.5 mol% sliver nanoparticles.