Improvement of the Optoelectrical Properties of a Transparent Conductive Polymer via a Simple Mechanical Pressure Treatment.

In this study, a simple and novel mechanical pressure treatment (MPT) was used to effectively improve the electrical and optical properties of ethylene glycol (EG)-doped PEDOT:PSS (EG-PEDOT:PSS) thin films, one of the most successful organic conductor materials ever which is are widely used in organic electronics because of their admirable film-forming property, high light transmittance, and excellent thermal stability. It is found that the conductivity of the EG-PEDOT:PSS films increased by 32% due to dramatically enhanced carrier mobility because an MPT improves the phase separation between PEDOT and PSS and then yields an interpenetrating conductive network. Meanwhile, the transmittance of the EG-PEDOT:PSS films in the near-infrared band was enhanced, and the surface roughness was reduced. These thin films retain their incredible flexibility as well; after 5000 times of 180° bending, the sheet resistance is basically unchanged. Considering that this MPT approach is already well developed in industrial applications, it is very hopeful to extend this technique in the field of organic electronics.