Theoretical investigation of the conducting properties of substituted phosphole oligomers

The conducting properties of phosphole oligomers have been investigated using density functional theory (DFT) at B3LYP/6-31G(d). Effects of electron-donor substituents (OCH3 and NHCH3) on the electrical conductivity of phosphole oligomers and polymers were studied. A significant reduction of the HOMO–LUMO energy gap (Eg), ionization energy (IE), and enhancing electron affinity (EA) has been obtained. Moreover, NHCH3 substituted oligomers show p-type conductivity regardless of the position of substitution where the hole injection rate oscillates between 104 and 1018. However, the OCH3 substituted oligomers at Cβ indicates p-type conductivity with hole injection rate of 1010–1014 and n-type conductivity when substituted at the P-center with the electron injection rates range between 102 and 106.