Excitons in van der Waals materials: from monolayer to bulk hexagonal boron nitride

Abstract

We present a general picture of the exciton properties of layered materials in terms of the excitations of their single-layer building blocks. To this end, we derive a model excitonic hamiltonian by drawing an analogy with molecular crystals, which are other prototypical van der Waals materials. We employ this simplified model to analyse in detail the excitation spectrum of hexagonal boron nitride (hBN) that we have obtained from the {\it ab initio} solution of the many-body Bethe-Salpeter equation as a function of momentum. In this way we identify the character of the lowest-energy excitons in hBN, discuss the effects of the interlayer hopping and the electron-hole exchange interaction on the exciton dispersion, and illustrate the relation between exciton and plasmon excitations in layered materials.

Accepted for Phys. Rev. B

References in corpus (4)

• Two Dimensional Atomic Crystals
• 2D materials and van der Waals heterostructures
• Two-Dimensional Material Nanophotonics
• {\it Ab--initio} finite temperature excitons

Cited by in corpus (5)

• Dimensionality and Anisotropicity Dependence of Radiative Recombination in Nanostructured Phosphorene
• Ab initio study of electromagnatic modes in two-dimensional semiconductors: Application to doped phosphorene
• Photo-Physical Characteristics of Boron Vacancy-Derived Defect Centers in Hexagonal Boron Nitride
• Comparison of long-range corrected kernels and range-separated hybrids for excitons in solids
• Gauge-invariant optical selection rules for excitons