Electrostatic modification of infrared response in gated structures based on VO2

TL;DR

This study explores how electrostatic doping affects the infrared response of VO2 in a transistor setup, revealing hole accumulation increases IR absorption during the insulator-metal transition, likely due to metallic island growth.

Contribution

It demonstrates the impact of electrostatic doping on IR response in VO2 and suggests a percolation mechanism involving metallic island growth during the phase transition.

Findings

IR absorption increases with hole accumulation in VO2

Effect persists after removing gate voltage

Supports percolation model of metallic island growth

Abstract

We investigate the changes in the infrared response due to charge carriers introduced by electrostatic doping of the correlated insulator vanadium dioxide (VO2) integrated in the architecture of the field effect transistor. Accumulation of holes at the VO2 interface with the gate dielectric leads to an increase in infrared absorption. This phenomenon is observed only in the insulator-to-metal transition regime of VO2 with coexisting metallic and insulating regions. We postulate that doped holes lead to the growth of the metallic islands thereby promoting percolation, an effect that persists upon removal of the applied gate voltage.