Effect of spin traps on charge transport in low-bandgap copolymer:fullerene composites

摘要: Abstract Light-Induced EPR study of magnetic, relaxation and dynamic parameters spin charge carriers background photoinduced in bulk heterojunctions composites formed by poly[2,7-(9,9-dioctylfluorene)- alt -4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole] (PFO-DBT) poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) with methanofullerene [6,6]-phenyl-C 61 -butyric acid methyl ester is described. A part polarons captured deep traps whose number energy depth are governed the structure, morphology a copolymer matrix also photon energy. Both exhibit photo-response within energy/wavelength 1.32–3.14 eV/940-395 nm region which wider than that other polymer composites. Magnetic, dynamics were shown to be their exchange interaction Specific causes selectivity these It was anisotropy mobility through reflects system dimensionality properties. The replacement PFO-DBT backbone PCDTBT leads increases ordering copolymer, decreases changes mechanism recombination. decay free interpreted terms trapping-detrapping diffusion heterojunctions.