The Study On Excited Dynamics Of Dye/TiO₂（101） Photoanode In Dye-sensitized Solar Cells

In this thesis the internal charges transfer properties of dye-sensitized solar cells（DSSC）were studied using density functional theory（DFT）based on the first principle.The numerical simulation was carried out to display the adsorption properties of dye molecules and geometry/electronic structures of Dye/TiO₂（101）systems with semiconductor anatase TiO₂ model as the anode and donor-conjugated-acceptor（D-π-A）structure organic dye molecules as photosensitizer.And,the separation and transfer mechanism of the interfacial charges were further analyzed.In order to improve the accuracy of electronic structure calculation results,the Coulomb Repulsion（U=6 eV,J=0.5 eV）is considered for Ti 3d orbital using DFT + U method in the calculations.Several Dye/TiO₂（101）systems were constructed in this work.Through the simulations,it was found that bidentate-bridging-type is the most stable configuration for dye molecules and anatase TiO₂（101）systems.Then the geometries and electronic properties of Dye/TiO₂（101）systems,such as density of states,charge density,Bader charges,etc.,were calculated.Finally,the whole process of interfacial electron transfer was studied and accurate electron injection time was calculated by analyzing the electronic properties of Dye/TiO₂（101）systems such as partial density of states and crystal frontier orbitals.