Poly{oxy-4,4'-octafluorobiphenylyleneoxy-alt-[1,4-phenylenevinylene(3-trimethylsilyl-1,4-phenylene)vinylene- 1,4-phenylene]} (PFSi) was synthesized and characterized to investigate its thermal, optical, electrical and xerographic properties. An LED (light emitting device) using PFSi as the light emitting layer exhibits maximum emission for blue light, but a high turn-on voltage. The origin of the low device performance was examined by investigating the photoconducting behavior. PFSi shows a high photoconductivity in the presence of electron accepters such as 5-nitroanthranilonitrile (5NAN), and the photoconductivity of PFSi is improved by introducing charge transport materials such as triphenylamine (TPA).