Dispersion Relations of Gold Nanoparticles on Complex Oxides
Fang-Yi Wen1*, Shih-Hsuan Chen1, Pei-Chi Hung1, Yen-Chin Huang1, Kuang-Yao Lo1, Yi-Chun Chen1
1Department of Physics, National Cheng Kung University, Tainan, Taiwan
* presenting author:温芳儀, email:b86137@gmail.com
Gold nanoparticles (AuNPs) have different optical properties varying with the size, the shape, the arrangement, and the environment of the particles. In recent years, AuNPs are of considerable interests in scientific research and extensively applied to electronic, optics, chemistry, and biosensing. One way to realize the interaction between light and surface plasmons is through the dispersion relation, which describes the relationship between energy (ω) and corresponding momentum (k). By analyzing dispersion relation, we can find out the key factors affecting surface plasmon resonance.
In this study, we investigated the AuNPs dispersion relations on complex oxide with various effective permittivities. We spread concentrated AuNPs solution on complex oxide substrates and films. We incident a collimated white light and then focused the light onto the sample put on the base of a prism. The total internal reflected light induced surface plasma resonance on the gold nanoparticles, and it resulted in the absorption signal showing the Plasmon dispersion relation. Furthermore, the total internal reflected light also can be analyzed by spectrometer. We obtained the different local surface plasmon resonance effect varying with effective permittivity of surroundings.

Keywords: gold nanoparticles, dispersion relation, local surface plasmon resonance