铋化物发光玻璃中银表面等离激元对铒离子的发光增强作用

局域表面等离激元可以由自由空间的光直接激发,这也是局域表面等离激元的优点所在。研究铋化物发光玻璃中纳米银颗粒的表面等离激元对铒离子发光的增强效应、进一步的提高铋化物发光玻璃中铒离子的发光性能很有意义。首先,测量了(A)Er 3+(0.5%)Ag(0.5%):铋化物发光玻璃与(B)Er 3+(0.5%):铋化物发光玻璃样品的吸收谱,发现(A)Er 3+(0.5%)Ag(0.5%):铋化物发光玻璃在约600.0 nm处有一个较弱的宽的银表面等离激元共振吸收峰。同时发现两者都有典型的铒离子的吸收峰,它们的吸收几乎完全一样:在波峰形状、峰值强度和峰值波长等方面都很相近。测量了(A)Er 3+(0.5%)Ag(0.5%):铋化物发光玻璃和(B)Er 3+(0.5%):铋化物发光玻璃样品的激发谱,发现有位于379.0,406.0,451.0,488.0和520.5 nm的5个550.0 nm可见光的可见激发谱峰,和位于379.0,406.5,451.0,488.5,520.5,544.0,651.5和798.0 nm的8个1531.0 nm红外光的红外激发谱峰,容易指认出依次为Er 3+的4I 15/2→4G 11/2,4I 15/2→2H 9/2,4I 15/2→(4F 3/2,4F 5/2),4I 15/2→4F 7/2,4I 15/2→2H 11/2,4I 15/2→4S 3/2,4I 15/2→4F 9/2和4I 15/2→4I 9/2跃迁的吸收峰,通过测量发现(A)Er 3+(0.5%)Ag(0.5%):铋化物发光玻璃相对于(B)Er 3+(0.5%):铋化物发光玻璃样品的可见和红外激发谱的最大增强依次分别是238%和133%。最后,测量了它们的发光谱,发现有位于534.0,547.5和658.5 nm的三组可见发光峰,容易指认出依次为Er 3+的2H 11/2→4I 15/2,4S 3/2→4I 15/2,4F 9/2→4I 15/2荧光跃迁。还发现红外发光峰位于978.0和1531.0 nm,依次为Er 3+的4I 11/2→4I 15/2和4I 13/2→4I 15/2的荧光跃迁。通过测量发现(A)Er 3+(0.5%)Ag(0.5%):铋化物发光玻璃相对于(B)Er 3+(0.5%):铋化物发光玻璃样品的可见和红外发光谱的最大增强依次分别是215%和138%。对于银表面等离激元增强铒离子发光的机理,认为主要为纳米银颗粒的局域表面等离激元共振,造成金属纳米结构附近产生的局域电场的强度要远大于入射光的电场强度,从而导致了金属纳米结构对入射光产生强烈的吸收和散射,进而导致了荧光的增强;即局域表面等离子体共振局域场的场增强效应。

Luminescence Enhancement of Erbium Doped Bismuth Glass by Silver Surface Plasmon

The localized surface plasmon can be directly excited by light in free space.This is also the advantage of local surface plasmon.So,it is very meaningful for us to study enhancement effect of erbium ion luminescence by surface plasmon of silver nanoparticles in bismuth luminescent glass,to further improve the luminescent properties of erbium ions.First,this paper measured the absorption spectra of(A)Er 3+(0.5%)Ag(0.5%):BiSiGa glass and(B)Er 3+(0.5%):BiSiGa glass sample.It was discovered that there is a weak broad resonance absorption peak of silver surface plasmon in the position of about 600 nm for(A)Er 3+(0.5%)Ag(0.5%):BiSiGa glass.It was also found that both have typical absorption peaks of erbium ions.Their absorptions were almost exactly the same.They were similar in peak shape,peak intensity and peak wavelength.Second,we measured the excitation spectra of(A)Er 3+(0.5%)Ag(0.5%):BiSiGa glass and(B)Er 3+(0.5%):BiSiGa glass sample.Five visible excitation peaks,in the positions of 379.0,406.0,451.0,488.0 and 520.5 nm respectively,have been found when monitored in 550.0 nm visible light.Same,eight infrared excitation peaks,in the positions of 379.0,406.5,451.0,488.5,520.5,544.0,651.5 and 798.0 nm respectively,have also been found when monitored in 1531.0 nm infrared light.It was easy to identify them as the absorption peaks of 4I 15/2→4G 11/2,4I 15/2→2H 9/2,4I 15/2→(4F 3/2,4F 5/2),4I 15/2→4F 7/2,4I 15/2→2H 11/2,4I 15/2→4S 3/2,4I 15/2→4F 9/2,and 4I 15/2→4I 9/2 of Er 3+ions in turn.It is discovered by measurement that the maximum enhancement of visible and infrared excitation spectra was 238%and 133%respectively for(A)Er 3+(0.5%)Ag(0.5%):BiSiGa glass relative to(B)Er 3+(0.5%):BiSiGa glass.Finally we measured the luminescence spectra.Three sets of visible emission peaks at 534.0,547.5 and 658.5 nm were found.It was easy to identify them as fluorescent transitions of 2H 11/2→4I 15/2,4S 3/2→4I 15/2 and 4F 9/2→4I 15/2 of Er 3+ions in turn.It was also found that the infrared emission peaks were at 978.0 and 1531.0 nm.They were fluorescence transitions of 4I 11/2→4I 15/2 and 4I 13/2→4I 15/2 of Er 3+ions in turn.It was discovered by measurement that the maximum enhancement of visible and infrared luminescence spectra was 215%and 138%respectively for(A)Er 3+(0.5%)Ag(0.5%):BiSiGa glass relative to(B)Er 3+(0.5%):BiSiGa glass.For the mechanism of erbium ion emission enhanced by silver surface plasmon,we think it is mainly that local surface plasmon resonance of silver nanoparticles causes the fact that the local electric field intensity generated near the metal nanostructure is much stronger than the electric field intensity of the incident light.This leads to metal nanostructures generating extremely strong absorption and scattering for incident light.This leads to enhance fluorescence.This is just the field enhancement effect of the local field of local surface plasmon resonance.