# Enhanced Light-Matter Interaction in Graphene/h-BN van der Waals Heterostructures

## TL;DR

This study demonstrates that graphene/h-BN heterostructures exhibit significantly enhanced and tunable light-matter interactions across a broad spectrum, enabling tailored optoelectronic properties through stacking arrangements.

## Contribution

It provides a comprehensive ab initio analysis showing how stacking modulates excitations and enhances light absorption in graphene/h-BN heterostructures, revealing new design possibilities.

## Key findings

- Broad spectral light absorption from near-infrared to UV
- Distinct excitations for each spectral region
- Stacking arrangement controls electron-hole distribution

## Abstract

By investigating the optoelectronic properties of prototypical graphene/hexagonal boron nitride (h-BN) heterostructures, we demonstrate how a nanostructured combination of these materials can lead to a dramatic enhancement of light-matter interaction and give rise to unique excitations. In the framework of ab initio many-body perturbation theory, we show that such heterostructures absorb light over a broad frequency range, from the near-infrared to the ultraviolet (UV), and that each spectral region is characterized by a specific type of excitations. Delocalized electron-hole pairs in graphene dominate the low-energy part of the spectrum, while strongly bound electron-hole pairs in h-BN are preserved in the near-UV. Besides these features, characteristic of the pristine constituents, charge-transfer excitations appear across the visible region. Remarkably, the spatial distribution of the electron and the hole can be selectively tuned by modulating the stacking arrangement of the individual building blocks. Our results open up unprecedented perspectives in view of designing van der Waals heterostructures with tailored optoelectronic features.