Highly conductive broadband transparent DMSO-doped PEDOT: PSS electrodes.

The conductive polymer poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) is considered as a flexible electrode material that can replace traditional electrodes. However, its performance optimization, practical application, and related research are primarily focused on a single band. In this study, we designed and prepared a broadband transparent electrode with a conductivity of up to 1300 S cm based on dimethyl sulfoxide (DMSO)-doped PEDOT: PSS. The as-fabricated PEDOT: PSS electrode achieved high transmittance in a wide range from a visible to terahertz band. The physical mechanism of its high conductivity and broadband transparency is studied by using a first-principle calculation. Furthermore, the transparent electrode exhibited excellent stability after 100,000 cycles of electrical cycling and 200°C of heating. Based on the transparent electrode, we fabricated a liquid crystal phase shifter with an extended operating range, showing its efficient driving performance as an electrode. The characterization and optimization of the properties of PEDOT: PSS in this work provide guidance for the application of PEDOT: PSS in broadband optical devices.