Ag-SiO_2复合纳米颗粒薄膜的制备及其光学特性研究

THE PREPARATION AND OPTICAL PROPERTIES OF Ag-SiO_2 COMPOSITE NANOPARTICLE FILMS

利用溶胶-凝胶法在玻璃基底上成功制备了Ag-SiO2复合纳米颗粒薄膜,SEM、TEM和XRD的表征分析表明Ag是以单晶纳米颗粒的形态均匀分散在SiO2基质中,形成了多孔状Ag-SiO2复合纳米颗粒薄膜。从Ag-SiO2复合纳米颗粒薄膜的光吸收谱发现,该复合薄膜中Ag纳米颗粒具有较强的等离子共振吸收峰,峰位在430 nm附近,随着复合薄膜中Ag、Si摩尔比的逐渐增大,等离子共振吸收峰不断增强且发生蓝移,蓝移量可达30 nm;研究AgSiO2复合纳米颗粒薄膜的光致发光特性发现,当激发波长为220 nm时,复合薄膜分别在330 nm和375 nm处出现了两个发光带,随着复合薄膜中Ag、Si摩尔比增大到0.11,两发光带均逐渐增强,继续增加Ag、Si摩尔比,两发光带又逐渐减弱,且375 nm处的发光带变化尤为显著。

The Sol-Gel technique is used to prepare the Ag-Si02 composite nanoparticle film on glass substrate. The SEM, TEM and XRD measurements of the films indicate that the single crystal metal Ag nanoparticles are uniformly embedded into the SiO2 particles. The Ag-SiO2 composite nanoparticle films are formed. The optical properties of the Ag-SiO2 composite nanoparticle films were studied. The results show that there is a surface plasmon resonance （SPR） peak around 430 nm in the optical absorption spectra of Ag-SiO2 composite nanoparticle films. As the molar ratio of Ag and Si increases, the intensity of SPR peak is gradually enhanced, and a blue shift of the SPR peak occurs. The amount of blue shift is about 30 nm. Furthermore, two photoluminescence （PL） peaks at 330 nm and 375 nm （ excitation wavelength is 220 nm） are observed in the PL spectra of the Ag-SiO2 composite nanoparticle films. In addition, the molar ratio of Ag and Si has a modulation on the two PL peaks.