Sub-60 mV per decade switching in ion-gel-gated In–Sn–O transistors with a nano-thick charge trapping layer

Abstract

In this paper, we present a new method for reducing the subthreshold swing (SS) of ionic-modulated oxide field-effect transistors (FETs) below 60 mV per decade. The electrical performances of ion gel-gated In–Sn–O FETs with and without a nano-thick Al₂O₃ charge trapping layer are compared and studied. A significant SS reduction in the In–Sn–O FETs is observed when naturally oxidized Al₂O₃ and an ion gel are used as the gate stacking dielectric layer. The back sweep SS reaches as low as ∼27 mV per decade and extends over three orders of magnitude in drain current. A theoretical explanation for these results based on energy band diagrams is presented. The proposed devices described here have the potential to open up new avenues for further development of low power electronics, as well as for energy efficient memristive devices and synaptic electronics.