Low-Voltage Oxide-Based Electric-Double-Layer TFTs Gated by Stacked Electrolyte/Chitosan Hybrid Dielectrics

摘要

Low-voltage oxide-based electric-double-layer (EDL) thin-film transistors (TFTs) gated by stacked $hbox{SiO}_{2}$ electrolyte/chitosan proton-conductor hybrid dielectric have been fabricated on glass substrates at room temperature. Such EDL TFTs exhibit a saturation mobility $(mu_{rm sat})$ of 7.8 $ hbox{cm}^{2}cdot hbox{V}^{-1}cdot hbox{s}^{-1}$, a subthreshold swing (S) of 100 mV/decade, a drain current on/off ratio $( hbox{I}_{rm on/off})$ of $hbox{7.8} times hbox{10}^{5}$ , and a threshold voltage $(hbox{V}_{rm th})$ of $-$0.48 V. After aging for one month in air ambient without surface passivation, such device shows $mu_{rm sat}$ of 3.5 $hbox{cm}^{2}cdot hbox{V}^{-1}cdot hbox{s}^{-1}$, $hbox{I}_{rm on/off}$ of $ hbox{1.2} times hbox{10}^{5}$, and S of 120 mV/decade. Control experiments demonstrate that devices gated by stacked $hbox{SiO}_{2}$ electrolyte/chitosan hybrid dielectrics show improved stability compared with TFTs gated by single chitosan or single $hbox{SiO}_{2}$ electrolyte gate dielectric.