Piezoelectric properties of graphene oxide from the first-principles calculations

TL;DR

This study uses first-principles calculations to explore the piezoelectric properties of graphene oxide, revealing significant responses and structural insights that suggest potential for MEMS/NEMS applications.

Contribution

It provides the first detailed computational analysis of piezoelectric responses in ordered graphene oxide structures, linking oxygen doping to piezoelectric behavior.

Findings

In-plane strain d31 up to 0.12% and 0.24 pm/V.

Deformation of oxygen-doped regions dominates strain response.

Higher oxygen concentration increases d31 in clamped GO, decreases in unzipped GO.

Abstract

Some highly ordered compounds of graphene oxide (GO), e.g., the so-called clamped and unzipped GO, are shown to have piezoelectric responses via first-principles density functional calculations. By applying an electric field perpendicular to the GO basal plane, the largest value of in-plane strain and strain piezoelectric coefficient, d31 are found to be 0.12% and 0.24 pm/V, respectively, which are comparable with those of some advanced piezoelectric materials. An in-depth molecular structural analysis reveals that deformation of the oxygen doping regions in the clamped GO dominates its overall strain output, whereas deformation of the regions without oxygen dopant in the unzipped GO determines its overall piezoelectric strain. This understanding explains the observed dependence of d31 on oxygen doping rate, i.e., higher oxygen concentration giving rise to a larger d31 in the clamped GO whereas leading to a reduced d31 in the unzipped GO. As the thinnest two-dimensional piezoelectric materials, GO has a great potential for a wide range of MEMS/NEMS actuators and sensors.