The effect of anchoring groups on the electro-optical and charge injection in triphenylamine derivatives@Ti6O12.

The triphenylamine (TPA), thiophene and pyrimidine are being used as efficient advanced functional semiconductor materials. In the present study, some new TPA donor–π–acceptor derivatives were designed where TPA moiety acts as donor, thiophene-pyrimidine π-bridge and acetic/cyanoacetic acid as acceptor. The ground-state geometries were optimized at B3LYP/6-31G** level of theory. The excitation energies and oscillator strengths were computed at TD-CAM-B3LYP/6-31G** (polarizable continuum model (PCM), in methanol) level of theory. The electronic, photophysical and charge transport properties were calculated wherever possible the computed values were compared with the available experimental as well as computational data. The electron injection (ΔG^inject), relative electron injection (ΔG^inject_r), electron coupling constants (∣V_RP∣) and light harvesting efficiencies (LHE) have been calculated and compared with referenced compounds. The energies of the lowest unoccupied molecular orbitals (E_LUMOs), diagonal bandgaps and energy level offsets were studied to shed light on the electron transport behavior. The effect of anchoring groups (acetic acid and cyanoacetic acid) was studied on the properties of interests in the dye and dye@Ti₆O₁₂. It was observed that after interaction of dye with the TiO₂ cluster intra-molecular charge transport enhanced from HOMO of the dye to LUMO of the semiconductor cluster. The cyanoacetic acid anchoring group leads the superior LHE, ΔG^inject and ∣V_RP∣ which might improve the solar cell performance. [ABSTRACT FROM AUTHOR]