Design of sensitizer with suitable frontier molecular orbital via substitution on starburst triphenylamine derivative.

Herein, a series of organic molecules were designed through locating different substituents on the compound (WD8-c-1) to develop their performances used as the sensitizers in the field of dye-sensitized solar cells. The geometry and relevant electronic properties of WD8-c-1 and its derivatives were simulated at the B3LYP/6-31G(d,p) level. The absorption spectra were calculated using the TD-PBE0/6-31+G(d,p) method. These calculated results show that the type and position of the substituents strongly affected the distributions of frontier molecular orbitals and the energy gaps for the WD8-c-1-derived molecules. The reorganization energies results reveal that their hole charge transfer rates are higher than that of the representative hole transport material. Moreover, the mobility of the representative WD8-c-1 derivative also has been simulated. The starburst triphenylamine with suitable substituent has the more suitable FMO energy to match those of TiO2, broad absorption region, smaller reorganization energies, and high hole mobility.