Laser-controlled field effect in graphene/hexagonal boron nitride heterostructures

TL;DR

This study demonstrates that laser irradiation can modify the local electronic properties of h-BN in heterostructures without causing structural damage, enabling new nanostructuring techniques.

Contribution

It introduces a laser-based method to alter the charge state of h-BN defects, providing a novel approach for nanostructuring in 2D heterostructures.

Findings

Laser irradiation changes Raman spectra and local charge state.

Modifications are stable over time and under electrical grounding.

No structural damage occurs during laser modification.

Abstract

The possibility of modification of the local properties of hexagonal boron nitride (h-BN) by laser irradiation is investigated. Investigations conducted using both Raman spectroscopy and electrostatic force microscopy were performed. Laser light induced modifications are found to cause no structural changes. However, they have impact on Raman spectra and local charge state of the material. They are also shown to be stable in time and during electrical grounding of the sample. The mechanism of photoionization of deep defects present in h-BN is proposed to explain the observed phenomenon. The discussed effect opens up new method of nanostructurization of h-BN based planar heterostructures.