Spectral (in)dependence of nonequilibrium charge carriers lifetime and density of states distribution in the vicinity of the band gap edge in F8BT polymer

Abstract

Photoelectric properties of the F8BT polymer are investigated by the Constant photocurrent method (CPM) based on the photocurrent spectra Δjph(hν) and absorption spectra αCPM(hν). The negligibly weak dependence of charge carriers lifetime on the photon energy is found for hν = 2.2–2.7 eV. The peculiarities of the absorption spectra and the photoconductivity spectra are revealed to be determined mainly by the Gaussian distribution of the density of states (DOS). The density of trap states in the F8BT polymer thin films in the exponential DOS is estimated to be 103 times higher than in the Gaussian DOS.