Effect of humidity on the hysteresis of single walled carbon nanotube field‐effect transistors

Abstract

Single walled carbon nanotube field‐effect transistors (SWCNT FETs) are attributed as possible building blocks for future molecular electronics. But often these transistors seem to randomly display hysteresis in their transfer characteristics. One reason for this is suggested to be water molecules adsorbed to the surface of the gate dielectric. In this study we investigate the hysteresis of SWCNT FETs at different relative humidities. We find that SWCNT FETs having atomic layer deposited (ALD) HfO2 – TiO2 – HfO2 as a gate dielectric retain their ambient condition hysteresis better in dry N2 environment than the more commonly used SiO2 gate oxide. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Origin of Hysteresis in Carbon Nanotube Field-Effect Transistors

“…When suspended CNT FETs were exposed to an ambient environment, hysteresis was observed in the current (Ids) versus gate voltage (Vg) characteristics when Vg was swept between -3 V to 3 V [19]. The hysteresis was advancing in nature, and its width (which is defined as the difference in the threshold gate voltages between the down and the up sweep directions) exhibited a strong dependence on ambient humidity, as was previously reported [13,20]. The hysteresis width has also exhibited exponential time dependence on the scanning time of a single sweep period with time constant of τ = 38 ± 4.2 sec (see Fig.…”

Water assisted gate induced temporal surface charge distribution probed by electrostatic force microscopy

“…This observation is in agreement with previous findings, which have reported that humidity affects hysteresis significantly. [26][27][28] Similar curves to those depicted in Fig. 7 were found when the gate bias was swept back from À2 V to zero.…”

Giant Moisture Responsiveness of VS2 Ultrathin Nanosheets for Novel Touchless Positioning Interface

“…I–V curves measured statically under different atmosphere with relative humidity (RH) gradient clearly show a huge decrease in the slope from low RH to high RH at 25 °C. As a humidity sensor, the maximum sensitivity (defined as R RH /R dry ) of the as‐established device can reach as high as 30, which well surpasses the humidity sensing performance of carbon nanotubes 25. Also, the response and recovering time (under stimulus of 90% RH) of our moisture detectors are only 30–40 s and 12–50 s, respectively, which are well shorter than the previously reported SnO 2 nanowire humidity sensor (120–170 and 20–60 s) 26.…”