Bilayer organic-inorganic gate dielectrics for high-performance, low-voltage, single-walled carbon nanotube thin-film transistors, complementary logic gates, and p-n diodes on plastic substrates

High-capacitance bilayer dielectrics based on atomic-layer-deposited HfO₂ and spin-cast epoxy are used with networks of single-walled carbon nanotubes (SWNTs) to enable low-voltage, hysteresis-free, and high-performance thin-film transistors (TFTs) on silicon and flexible plastic substrates. These HfO₂-epoxy dielectrics exhibit excellent properties including mechanical flexibility, large capacitance (up to ca. 330 nF cm ^-2), and low leakage current (ca. 10^-8 A cm^-2); their low-temperature (ca. 150°C) deposition makes them compatible with a range of plastic substrates. Analysis and measurements of these dielectrics as gate insulators in SWNT TFTs illustrate several attractive characteristics for this application. Their compatibility with polymers used for charge-transfer doping of SWNTs is also demonstrated through the fabrication of n-channel SWNT TFTs, low-voltage p-n diodes, and complementary logic gates.