[21p-P17-1~18] 12.2 Characterization and Materials Physics

[21p-P17-3] Redox Reaction in Single-Molecule Junction Characterized by Surface-Enhanced Raman Scattering

〇Shuji Kobayashi¹, Satoshi Kaneko¹, Kazuhito Tsukagoshi², Tomoaki Nishino¹ (1.Tokyo Tech., 2.NIMS MANA)

Keywords:single-molecule junction, surface enhanced Raman scattering, electrochemical measurement

Redox reaction on single-molecule junctions (SMJs) has attracted wide attention due to its potential application to molecular devices. In this study, we simultaneously measured electrical conductance and surface-enhanced Raman scattering (SERS) spectra of α-terthiophene SMJs under the control of electrochemical potential between 0.0 V and 0.8 V vs Ag/AgCl. When electrochemical potential reached 0.8V, the intensity of SERS spectra was drastically enhanced, and the peak emerged at 1590 cm^-1 in addition to the peaks observed in the initial state. The conductance was synchronically enhanced with the intensity of the SERS spectra. Theoretical calculation of Raman spectra suggests that the additional peak observed at 1590 cm^-1 originate from cation state of α-terthiophene. Therefore, conductance enhancement is attributed to the change in electronic state caused by oxidation of α-terthiophene in SMJs.