Transient absorption characteristics of silole derivative doped fluorene polymer fixed film

Abstract

We reported an improved photoconductive characteristics by doping 1,1-dimethyl-2,5-bis(N,N-dimethylaminophenyl)-3,4-diphenylsilole (NMe_2-silole) into poly(dioctylfluorenyl-co-benzo-thiadiazole) (F8BT). In this report, we investigated transient absorption characteristics at 3440nm to estimate the mechanism of the improved photoconductive characteristics. By adding NMe_2-silole, the long-lived optical density change between 500 to 1000ps was increased. This result indicates the high carrier dislocation efficiency caused high device performances because the long-lived optical density change relates the amount of photo-excited carriers in an organic layer.