Characterization of organic electroluminescent devices introducing fluorine-containing polyimide to hole-transporting layer

In the present study, we introduced fluorine-containing polyimide as a matrix polymer to a hole-transporting layer (HTL). The devices consisting of two organic layers were fabricated: ITO/TPD-dispersed polyimide–Alq3–Al devices. The polyimide used in this work was poly(hexafluoropropane dianhydride-co-4,4’-oxydiphenylene) (6FDA-ODA PI). The device performances were affected by the composition of triphenylamine derivative (TPD) and polyimide in the HTL. On increasing the concentration of TPD in the HTL, the relative electroluminescence (EL) and power efficiency increased. When the weight ratio of TPD to 6FDA-ODA PI was 70:30, the TPD706FDA30 device exhibited the lowest turn-on voltage (ca. 10 V) and the best relative EL and power efficiency.