Charge-Transfer and SERS Coupling on TiO<sub>2</sub>
- 1 Department of Physical Sciences, Eastern Connecticut State University, Willimantic, CT, USA
- 2 Department of Physical Sciences, Eastern Connecticut State University, Willimantic, CT, USA
Abstract
We report the SERS enhancements of Raman forbidden surface modes of TiO 2 in different sized TiO 2 crystals. This current study utilizes the relationship between the vibronic coupling and the degree of charge-transfer to explain the differences of Surface Enhanced Raman Scattering (SERS) enhancements. Our study shows a direct correlation between the degree of charge-transfer and vibronic coupling. This relationship suggests that charge-transfer between the N-719 dye and TiO 2 due to vibronic coupling plays a fundamental role in SERS enhancements. Furthermore, this study shows a strong dependence of the enhancements of the N-719 dye molecular modes to that of the surface modes. This indicates that the mechanism that governs the enhancements of the surface modes in TiO 2 crystals most likely also dictates the enhancements of the N-719 dyes.
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