Effect of high voltage electric field on structure and property of PEDOT : PSS film

Low electrical conductivity of PEDOT : PSS film is to some extent a limit for its wide application. To solve this problem, the high voltage electric field was used to improve the film's electrical conductivity and its effects on the film's structure and properties were investigated. The PEDOT : PSS film was prepared on quartz substrate with spin coating. Visible light transmittance of the prepared film was tested with UV-Visible spectroscopy and chemical structure was measured with Fourier transform Raman spectroscopy (FTRM). The surface morphology was characterized with AFM, and electrical conductivity was measured with Hall effects measurement. The results showed that with the increase of the electric field, the electrical conductivity of PEDOT : PSS film was boosted rapidly at first, and then improved slowly when the electric field was above 200 kV/m. The film's electrical conductivity improved more than 17 times in total from 0.51 $\cdot$ 10$^{-3}$ up to 8.92 $\cdot$ 10$^{-3}$ S/m. However, the film's visible light transmittance decreased only a little with the increase of the electric field, not more than 3%. In addition, despite little change in the chemical structure of the PEDOT : PSS film, its surface roughness increased significantly with the increase of the electric field intensity.