Reversible modulation of metal-insulator transition in VO2 via chemically-induced oxygen migration

TL;DR

This paper demonstrates a reversible method to control the metal-insulator transition in VO2 films by using a water-soluble layer to induce oxygen migration, enabling potential applications in electronic and iontronic devices.

Contribution

It introduces a novel, reversible oxygen stoichiometry engineering technique using a dissolvable layer to modulate the MIT in VO2 films.

Findings

Reversible suppression and recovery of MIT in VO2 achieved.

Oxygen migration confirmed by transport, structural, and computational analysis.

Method enables control of electronic properties via oxygen stoichiometry.

Abstract

Metal-insulator transitions (MIT),an intriguing correlated phenomenon induced by the subtle competition of the electrons' repulsive Coulomb interaction and kinetic energy, is of great potential use for electronic applications due to the dramatic change in resistivity. Here, we demonstrate a reversible control of MIT in VO2 films via oxygen stoichiometry engineering. By facilely depositing and dissolving a water-soluble yet oxygen-active Sr3Al2O6 capping layer atop the VO2 at room temperature, oxygen ions can reversibly migrate between VO2 and Sr3Al2O6, resulting in a gradual suppression and a complete recovery of MIT in VO2. The migration of the oxygen ions is evidenced in a combination of transport measurement, structural characterization and first-principles calculations. This approach of chemically-induced oxygen migration using a water-dissolvable adjacent layer could be useful for advanced electronic and iontronic devices and studying oxygen stoichiometry effects on the MIT.