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

Abstract 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.