Amorphous, glassy, organic semiconductors

Polarisation spectroscopy of thin films of F8BT poly(9,9-dioctylfluorene-alt- benzothiadiazole) polymer

T. E. Zedomi^a, L. V. Kotova^ab, A. M. Smirnov^b, V. P. Kochereshko

^a Ioffe Institute, St. Petersburg
^b Lomonosov Moscow State University, Faculty of Physics

Abstract: The transmission spectra feature of F8BT poly(9,9-dioctylfluorene-alt-benzothiadiazole) polymer films were studied, for which significant optical anisotropy was established. The effect of temperature heating and additional irradiation on the anisotropy of optical properties was studied. It was found that UV irradiation leads to a significant increase in the refractive index difference along and across some axis lying in the sample plane. The temperature effect partially attenuates this difference. The observed phenomenon can be explained by the destruction of chemical bonds in polymer chains of poly(9.9-dioctylfluorene-alt-benzothiadiazole).

Received: 13.05.2025
Revised: 22.06.2025
Accepted: 25.06.2025

DOI: 10.61011/FTP.2025.03.61095.8158