Vapor-Phase Deposited Ultrathin Polymer Gate Dielectrics for High-Performance Organic Thin Film Transistors

Abstract

A series of new ultrathin polymer dielectric layers (sub-40 nm) is synthesized via initiated chemical vapor deposition (iCVD) for application in low-power, flexible organic thin-film transistors (OTFTs): poly(ethylene glycol dimethacrylate) (pEGDMA), poly(isobornyl acrylate) (pIBA), and poly(1H, 1H, 2H, 2H-perfluorodecyl acrylate) (pPFDA). The iCVD process is a solvent-free, vapor-phase process to deposit various kinds of functional polymer films with a high purity. The iCVD polymer dielectric layers commonly exhibit low leakage current densities (J(i)) less than 10(-8) A cm(-2) in the range of +/- 3 MV cm(-1), high breakdown field (E-break) over 4 MV cm(-1), and excellent flexibility up to a tensile strain of 3.3%. Hysteresis-free, low-voltage OTFTs made of the iCVD dielectric layers are demonstrated with various kinds of n- and p-type semiconductors. The superior performance of the iCVD dielectrics will enable the polymer films to play a pivotal role in developing various types of future organic electronic devices.