Theoretical investigation of the conducting properties of substituted phosphole oligomers

► Electrical conductivity of phosphole oligomers were studied using B3LYP/6-31G(d). ► The OCH3 and NHCH3 substituents were used for testing the electrical conductivity. ► A significant reduction of the HOMO-LUMO energy gap, ionization energy, and enhancing electron affinity has been obtained. ► An enhanced electron affinity was observed for the substituted phosphole oligomers. ► NHCH3 shows p-type conductivity regardless of the position of substitution.