Investigation of electronic and optical properties of organic poly(3-hexylthiophene)(P3HT) polymers used in solar cells

Poly(3-hexylthiophene-2,5-diyl) (P3HT) and its derivatives are good organic semiconductors and have various applications in many fields such as photovoltaic systems and organic light-emitting diodes. In this study, the basic physical and chemical properties of the monomers that form the P3HT polymer chain by adding Chlorine and Fluorine to the structure of P3HT were examined theoretically. Gaussian 09 was used in the calculations and GaussView 5.0 software packages were used to convert the structures into visuals. It was found that the bond lengths and bond angles of the isolated molecule were greater than the doped P3HT. The band gap was calculated for fluorine-doped P3HT and chlorine-doped P3HT. Doped molecules were found to be more reactive than their isolated forms because they had lower chemical hardness values. Results on nonlinear optical (NLO) properties show that doped P3HT has good first-order hyperpolarizability. UV-Vis absorption values and open circuit voltage were also calculated. According to the results, the doped molecules have potential applications for photovoltaic devices due to good electron transfer.