[10p-N404-1~14] 4.1 Plasmonics and Nanophotonics

▲ [10p-N404-2] Large-area Raman spectral nano-analysis of 2D materials by long-term TERS imaging

〇Toki Moriyama¹, Ryo Kato³, Takayuki Umakoshi^1,2,4, Prabhat Verma¹ (1.Osaka Univ., 2.Osaka Univ. Inst., 3.Tokushima Univ., 4.JST PRESTO)

Keywords:tip-enhanced Raman spectroscopy, nanoimaging, 2D material

Tip-enhanced Raman spectroscopy (TERS) can acquire chemical information with a nanoscale spatial resolution by exciting near-field light at the nanoscale metallic-tip apex. However, TERS configuration easily collapses by thermal drift, and imaging time in TERS is generally limited to around 30 minutes. This also limits the image size to around 1 square µm. Therefore, we had developed the 3D drift-compensation system to sustain the TERS setup and overcome the limitation. Here, I report prodigious spectral analysis of a large-area tungsten disulfide (WS2) bilayer based on long-term TERS imaging using 3D drift-compensation system. Consequently, it was found that the spectra had a quantity of chemical information, such as existence of defect modes and strong photoluminescence signals. In a nod to these spectral features, we investigated the structure of the sample over the large-area with a nanoscale spatial resolution.