Theoretical investigations on the electronic and optical characteristics of fused-ring homopolymers: Comparison of oligomer method and PBC−DFT method

The electronic and optical characteristics of conjugated polymers are the curial parameters for their photovoltaic and photonic applications. Here, the electronic and optical properties of six selected homopolymers were studied using two methods: oligomer method and PBC−DFT method. The calculated results show, PBC/B3LYP/6-31G* is preferable to weakly conjugated homopolymers, while the oligomer approach using linear fit at B3LYP/6-31G* level, reproduced well band gaps for stronger conjugated homopolymers. The results also indicate that the calculated absorption spectra using TD-B3LYP/6-31G* at trimer model are in agreement with the available experiments, however the Meier fit of oligomers highly overestimates the experimental data.