Effect of doping is investigated by applying iodine dopant to plasma polymerized fluorene (C13H10)-type thin films utilizing two separate techniques: ex-situ and in-situ doping. In this study, the thin films are produced using a mixture of biphenyl and methane in a capacitively coupled glow plasma system. Produced thin films are characterized using a fourier transform infrared spectrometer, an ultraviolet-visible spectrometer, a scanning electron microscope, and a two-point probe technique of the current - voltage characteristics. The results show that the in-situ doping technique is more effective than the ex-situ doping technique based on the improvements observed. (C) 2019 Elsevier Ltd. All rights reserved.