The Role of Time in the Structural Ordering of Poly-3-Hexylthiophene

An investigation into the influence of annealing time on structural ordering of Poly-3-Hexylthiophene has been performed via analyses of absorbance data, on the premise that ordering status is reflected in optoelectronic properties. Thin films heated from 0 to 100 min were examined. It was found that 20 min annealing yields a thin film with the highest structural ordering, with density of states of 6.08 ± 0.16 × 10³⁸ m^-3 kg^-1 and carrier density of 5.54 ± 0.14 × 10⁸ m^-3. Samples annealed beyond 40 min exhibited optoelectronic traits midway between unannealed and 20 min annealing. The results demonstrated that during thermal treatment at a fixed temperature, the structural ordering and conformity continuously change with time, affecting the optoelectronic properties, thus emphasizing the necessity of the "time-profile" to determine the appropriate annealing time for a specific application of the polymer.