Transverse charge transport in inkjet printed poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)

• Transverse (z) alignment of PEDOT structures in AFM of inkjet printed PEDOT:PSS.
• This explains the 1D-VRH transverse charge transport for inkjet printed PEDOT:PSS.
• Hence, z conductivity is 600x higher for inkjet printed than for spin coated films.
• These are important findings for transverse conduction OPV and OLED applications.

Transverse (z) alignment of PEDOT grains was demonstrated in inkjet printed PEDOT:PSS. This explained the superior transverse charge conduction mode in inkjet printed PEDOT:PSS films, best fitted by the Efros-Shklovskii 1D-VRH (variable range hopping) model in this study compared with spin coated PEDOT:PSS films, which have demonstrated layers of generally in-plane aligned PEDOT:PSS grains. The findings of this study, regarding the microstructure of inkjet printed PEDOT:PSS films and their transverse charge transport model, justify measurements of the transverse conductivity of inkjet printed films in this study being 600 times higher than that of spin coated films. In addition, it was found that the addition of 5 wt% DMSO in the printing PEDOT:PSS ink lowers the workfunction by 3% approximately.

Figure optionsDownload as PowerPoint slide