We will present theoretical results we have recently obtained concerning the Enhanced Raman Scattering (ERS) of a Dopamine molecule adsorbed on a TiO2 nano-particle. Raman enhanced response for molecules adsorbed on metallic nano-particle is mainly due to plasmon resonance excitation. In the case of TiO2 semi-conducting nano-particles, the enhancement can not be explained in term of plasmons. We will explore the mechanisms responsible for ERS with semi-conducting nano-particle, and how to model them. We have developed an efficient method for calculating resonance Raman spectrum for such systems, which posses the peculiar property that their excited electronic states decay in a short time. Numerical implementation of this method along time TD-DFT calculations will be presented.<br/>We will also present a model for these hybrid systems which is a Fano-Friedrichs-Anderson model but including a relaxation process described in terms of a Liouville-Lindblad equation. The complete optical response: fluorescence emission, Rayleigh and Raman scattering, calculated in the framework of this model, will be presented. In particular, the conditions for the observation of Fano interferences profile in the emission line shape of such hybrids will be investigated.

Optical response of molecule — semiconducting nanoparticle hybrids

249th National Meeting (2015)

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