Theoretical Investigation of New Organic Compounds (D-π-A) Based on Triphenylamine as Photosensitizer for Dyesensitized Solar Cells

The current work involved suggestion of a new material "D-π-A system" for use in solar cells as organic dyes sensitized. The ground state estimations are done by utilizing the hybrid functional "B3LYP" with 6-311G(d, p) basis set on density functional theory (DFT) method in gas phase. Besides, the TD-DFT was selected with same functional to modulate the electronic absorption spectra and charge-transfer capabilities of the dyes analyzed in this study. The effects of introducing different groups as π-bridge on the properties of these materials were examined with intending to confirm the connection between compounds structure and its properties. In addition, various electronic, optical, chemical reactivity and optical parameters were determined from the fully optimized structures. The results demonstrate these materials can be utilized as organic sensitizers for solar cell because of its properties and probability of the electron injection process from each studied molecule to the E_CB "conduction band" of TiO₂ and PCBM and the subsequent regeneration are possible, finally the electrons transfer will be simple from the examined dyes to TiO2 or PCBM.