Surface enhanced Raman spectroscopy of epitaxial BFO films
Pei-Chi Hong1*, Yen-Chin Huang1, Yi-Chun Chen1, Yen-Lin Huang2, Jan-Chi Yang2, Ying-Hao Chu2
1Physics, National Cheng Kung University, Tainan, Taiwan
2Material Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
* presenting author:洪佩琪,
Raman spectroscopy can give us important information about the lattice vibration mode. However, to detect thin films, the background signals which originate from substrate are usually so strong to overwhelm those of the film. Surface enhanced Raman Spectroscopy (SERS) providing enhanced surface intensity and high spatial resolution could solve this problem. So far, there are two major mechanisms of SERS. The electromagnetic mechanism described that localized surface plasmon increases the probability of Raman scattering with metal nanoparticle. The chemical mechanism described that photon will excite the free electrons of metal nanoparticles to the LUMO state of sample under test, and it results in the effect similar to the resonance Raman spectroscopy. In our study, we use ferroelectric lithography to attract Au nanoparticles. The line density and orientation of the gold nano-particles could be manipulated in the surface of BiFeO3 (BFO) films. Conducing atomic force microscope was used to test the conductivity of gold nano-particles. The SERS effect of BFO is affected by the arrangement of gold nanoparticles and the polarization direction of light.

Keywords: Surface enhanced raman spectroscopy , Raman spectroscopy , BiFeO3(BFO), ferroelectric lithography