Tuning the dedoping process of PEDOT:PSS films using DBU-solvent complexes

Abstract

"In this study, we report a successful simple technique to dedope pristine PEDOT:PSS films at room temperature by dipping the films into 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) mixes with different solvents such as dimethyl sulfoxide (DMSO), acetonitrile (MeCN) and deionized (DI) water. The treated PEDOT:PSS films presented a strong ?-?* absorption band centered at 630?nm, which indicated that the PEDOT chains were being reduced to their neutral state. The dedoping efficiency of the PEDOT chains depended on the used DBU complex, the DBU concentration in the mixture as well as the immersion time, which was quantified comparing the relative intensities between the ?-?* and the polaronic (centered around 900?nm) bands. The best dedoping efficiencies of PEDOT:PSS films were obtained using MeCN/DBU or DI water/DBU complexes, as the polaronic band almost disappeared, whereas using DMSO/DBU complex the polaronic band was always present. This difference was mainly related to the degree of basicity of the DBU complexes and solubility extent of PEDOT:PSS in the various solvents. Finally, thick dedoped PEDOT:PSS films showed a strong yellow emission when they were excited with a 488?nm laser. The encapsulated dedoped thick films endured up to 50?mW of laser power without impacting their luminescent and physical properties."