Highly conductive and low-work-function polymer electrodes for solution-processed n-type oxide thin-film transistors. Issue 1 (2nd January 2023)

• Record Type: Journal Article
• Authors: Huseynova, Gunel; Boampong, Amos Amoako; Yu, Kyeong Min; Lee, Ye-Seul; Lee, Jonghee; Kim, Min-Hoi; Lee, Jae-Hyun
• Is Part Of: Journal of information display. Volume 24:Issue 1(2023)
• Page Start: 47
• Page End: 56
• Publication Date: 2023-01-02
• Subjects: Solution-processed oxide thin-film transistors -- low work function -- PEDOT:PSS -- n-doping -- reduced methyl red; Information display systems -- Periodicals; Information display systems; Electronic journals; Periodicals; 621.381542
• DOI: 10.1080/15980316.2022.2126017
• Languages: English
• ISSNs: 1598-0316

Abstract

Abstract : We present an n- doped poly(3, 4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) polymer and its application in n -type oxide thin-film transistors (OxTFTs) as a source and drain electrode material. A reduced molecule of a cationic dye, methyl red (MR), was used as an effective solution-processed n -type dopant. The sequential de-doping and doping of the initially p -doped PEDOT:PSS polymer with the reduced MR (r-MR) effectively removed positive charges via cancellation by the added electrons. As a result, the electron conductivity of PEDOT:PSS increased from 3.4 S/cm to ∼51 S/cm, while its work function decreased from 4.8 eV to 3.5 eV. This is one of the lowest values of the work function reported for PEDOT:PSS. The n -doped PEDOT:PSS films were eventually applied as a suitable material to fabricate the contact electrodes of solution-processed bottom-gate top-contact amorphous indium-gallium-zinc oxide-based OxTFTs. The resultant devices exhibited electron mobility over ten times better compared to those with undoped PEDOT:PSS electrodes. Therefore, we suggest this method as a highly suitable and low-cost technique for improving electron transport in PEDOT:PSS and all solution-processed conductors. Further investigations with this method are expected to expand the application of PEDOT:PSS to other sectors of optoelectronics.