Computational Modeling of Plasmon-Enhanced Light Absorption in a Multicomponent Dye Sensitized Solar Cell

Plasmon-enhanced light absorption in a multicomponent Ag/Ag2O/TiO2/N3 dye-sensitized solar cell (DSSC) core−shell nanostructure is studied using a hybrid quantum mechanics/classical electrodynamics (QM/ED) methodology in which the Ag/Ag2O/TiO2 nanostructure is treated by the finite-difference time-domain method and the N3 dye is treated by real-time time-dependent density functional theory. As part of this modeling, the undetermined thickness of the nonplasmonic Ag2O layer on the Ag/Ag2O/TiO2 particle was estimated by comparing the computed plasmon wavelength with experimental results. Also, absorption cross sections for the N3 dye were calculated for different locations of the dye on the TiO2 surface. The spatially averaged absorption cross sections for different thicknesses of TiO2 were evaluated and used to estimate the relative incident photon conversion efficiency. Encouragingly, it is found that the QM/ED calculations can well reproduce the factor of ∼10 experimental extinction difference spectrum and the photocurrent enhancement factor associated with DSSCs. Our studies demonstrate that the hybrid QM/ED methodology provides a useful guide to the systematic design of plasmon-enhanced DSSCs for achieving optimum photovoltaic efficiency.