Photoactivities of thiophene monomer/polymer transition in gel–based photoelectrochemical assembly: A theoretical/experimental approach

Photoactivities of bithiophene and/or terthiophene monomers and their mixtures were studied before and after being subjected to in situ oxidative electropolymerization in gel electrolyte (GE). Measured band gaps and density functional theory calculations supported the presence of oligomers in conjunction with the expected polymers. More oligomers formed during polymerization of the mixed monomers than with pure monomers. The generated photocurrent from the polymer/oligomer was always greater than that of the monomer. These results support the assumption that increasing π-bond conjugation leads to better e/h formation, and charge separation. The study also shows that the increase of the TerTh percentage in the monomer’s mix increased the generated photocurrent by the existing polymer/oligomer mix in a linear monotonic relationship