Au纳米颗粒的形状和尺寸对表面等离子体的影响

Influence of Shape and Size of Au Nanoparticles on the Surface Plasmon

通过调控Au纳米颗粒的形状和尺寸,研究了Au纳米颗粒的形状和尺寸与表面等离子体之间的关系。通过直流磁控溅射的方法在外延片上溅射Au薄膜,并采用快速热退火和常规热退火两种方式对其进行热退火,制备出Au纳米颗粒。使用不同热退火方式、不同热退火温度及不同Au薄膜厚度来改变Au纳米颗粒的形状和尺寸,并对Au纳米颗粒的表面形貌及它的消光谱进行了分析,对比了不同形貌的Au纳米颗粒对表面等离子体共振特性的影响。实验结果表明,使用普通热退火制备的Au纳米颗粒形状接近球体,而使用快速热退火得到的Au纳米颗粒的形状更接近棒体;随着热退火温度的升高,表面等离子体的共振波长发生红移;随着Au薄膜厚度的增加,表面等离子体的共振波长也发生红移。

The relationship between the shape and size of Au nanoparticles and surface plasmon resonance （SPR） wavelength was studied. Firstly, Au layer was sputtered onto the epitaxial wafers and the thermal annealed in ambient Nz with rapid thermal annealing and conventional thermal annealing, respectively, thus Au nanoparticles were produced. The shape and size of Au can be controlled by changing the method of thermal annealing, thermal annealing temperature and the thickness of Au film. The surface morphology and extinction spectra of the Au nanoparticles were measured and the influence of different morphologies of Au nanoparticles on SPR was analyzed. The results show that the shape of Au nanoparticles fabricated with conventional thermal annealing is close to spheres, while the shape of the Au nanoparticles produced by rapid thermal annealing is close to rods. SPR wavelength red shifts happen with the increase of both the thermal annealing temperature and the thickness of Au film.