Paramagnetic defects and photobleaching effects of polymer PCDTBT thin films with the admixtures of fullerene PCBM, beta-carotene and fluorinated carbon nanotubes

The influence of the additives to the thin film of the semiconducting polymer PCDTBT on the kinetics of its photooxidation in air was revealed through changes in the UV–vis absorption spectra and the EPR spectra of the paramagnetic defects. These defects appeared in the initial stage of the PCDTBT photooxidation, and the kinetics of their generation and decay reflected the impact of the additives on PCDTBT stability. While a small amount of PCBM and beta-carotene resulted in the accelerated photooxidation, the addition of fluorinated carbon nanotubes stabilized PCDTBT.