Doped PEDOT:PSS electrodes, patterned through wettability control, and their effects on the electrical properties of polymer thin film transistors

Abstract

The water−based conductive polymer, poly(3,4−ethylenedioxythiophene), doped with poly(styrene sulfonate) (PEDOT:PSS), has received much attention for its utility as a printable electrode due to its transparency, thermal stability, and processability; however, the electrical properties of devices prepared with printed PEDOT:PSS electrodes are generally inferior to those of devices fabricated with evaporated metal electrodes or their inorganic counterparts. Here, we show that the electrical performances of polymer thin film transistors could be improved by doping the PEDOT:PSS chains used as source and drain electrodes. The addition of HAuCl4 to the PEDOT:PSS solution increased the electrical conductivity and work function of the electrodes. The PEDOT:PSS film doped with 10 mM HAuCl4 provided a field effect mobility exceeding 0.01 cm2V−1s−1, a factor of 7 greater than the value obtained from the device prepared with pristine PEDOT electrodes.