Aminosilane monolayer-assisted patterning of conductive poly(3,4-ethylenedioxythiophene) source/drain electrodes for bottom contact pentacene thin film transistors

This paper reports the fabrication of organic thin film transistors (OTFTs) with conducting poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes using a bottom-up process consisting of the selective growth of PEDOT on a pre-patterned (3-aminopropyl)trimethoxysilane (APS) monolayer. The newly developed bottom-up process produced strongly adherent, selectively and uniformly patterned PEDOT films on oxidized substrates. In addition, the PEDOT/APS double structure showed an approximately one order of magnitude lower leakage current and contact resistance than the Au/Ti electrodes. The lower leakage current was due to the additional blocking effects by APS monolayer in the PEDOT/APS structure; the lower contact resistance was attributed to the better quality of pentacene films formed on PEDOT electrodes than that of the gold electrodes.