Printed carbon nanotube thin film transistors based on perhydropolysilazane-derived dielectrics for low power flexible electronics

Abstract

Electric double layer (EDL) electrolyte dielectrics have attracted great interest for low voltage and low power consumption portable thin film transistor (TFT) devices and circuits due to their high gate modulation efficiency. In this work, fully printed single-walled carbon nanotube (SWCNT) TFTs are fabricated using proton conducting inorganic perhydropolysilazane (PHPS) derivatives as the EDL dielectrics at low frequencies (<1 kHz) that can be processed in humidity even at quite low temperature (<100 °C) and relatively short reaction time (∼10 min). Fabricated fully printed SWCNT TFTs exhibit excellent electrical properties with low operating voltage (±1 V), high on/off ratio (∼106), small subthreshold swing (70–110 mV/dec), good stability and the average carrier mobility of 6.3 cm2 V−1 s−1. In addition, the precise control of the SWCNT TFTs’ threshold voltage and polarity (from depleted p-type to enhanced p and n-type, and well-balanced ambipolar) is successful demonstrated by adjusting the printable sc-SWCNT ink concentrations and electron doping technology (using ethanolamine as the electron doping agent). Furthermore, fully printed flexible complementary metal oxide semiconductor (CMOS) and CMOS-like inverters based on as-prepared SWCNT TFTs represent extremely low static power consumption (0.1 pW/μm and 0.05 pW/μm, respectively), high voltage gain (up to 45 at VDD = 0.7 V) and relatively large noise margins.