Reversible Gas Sensing by Ferroelectric Switch and 2D Molecule Multiferroics in In2Se3 Monolayer

TL;DR

This study uses first-principles calculations to demonstrate reversible gas adsorption on ferroelectric In2Se3 monolayers, revealing potential for gas sensing, magnetic switching, and spintronic applications through ferroelectric polarization control.

Contribution

It uncovers the reversible gas adsorption mechanism on In2Se3 monolayers and introduces the concept of 2D molecule multiferroics with polarization-dependent magnetic properties.

Findings

Gas adsorption behavior is reversible and controllable by ferroelectric switching.

Paramagnetic gases like NO and NO2 induce surface magnetism sensitive to polarization.

Two NO molecules can couple ferromagnetically with a polarization-dependent Curie temperature up to 50K.

Abstract

Two-dimensional ferroelectrics are important quantum materials which have found novel application in nonvolatile memories, however, the effects of reversible polarization on chemical reactions and interaction with environments are rarely studied despite of its importance. Here, based on the first-principles calculations, we found distinct gas adsorption behaviors on the surfaces of ferroelectric In2Se3 layer and the reversible gas caption and release controlled by ferroelectric switch. We rationalize the novel phenomena to the synergistic effect of the different electrostatic potential and electron transfer induced by band alignments between frontier molecular orbitals of gas and band edge states of substrate. Excitingly, the adsorption of paramagnetic gas molecules such as NO and NO2 can induce surface magnetism, which is also sensitive to ferroelectric polarization direction of In2Se3, indicating the application of In2Se3 as threshold magnetic sensors or switcher. Furthermore, it is suggested two NO molecules prefer to ferromagnetically couple with each other, the Curie temperature is polarization dependent which can reach up to 50K, leading to the long-sought 2D molecule multiferroics. The ferroelectric controllable adsorption behavior and molecule multiferroic feature will find extensive application in gas caption, selective catalytic reduction and spintronic device.