Electrostatics of electron-hole interactions in van der Waals heterostructures

TL;DR

This paper investigates dielectric screening effects on electron-hole interactions in van der Waals heterostructures, introducing a transfer matrix method for efficient potential calculations and comparing theoretical results with experimental data.

Contribution

A simple transfer matrix method for calculating electron-hole interaction potentials in layered heterostructures is developed and validated against experimental results.

Findings

Transfer matrix method enables low-cost, accurate potential calculations.

Calculated exciton binding energies align with recent experimental measurements.

Different potential models provide consistent insights into exciton behavior in 2D materials.

Abstract

The role of dielectric screening of electron-hole interaction in van der Waals heterostructures is theoretically investigated. A comparison between models available in the literature for describing these interactions is made and the limitations of these approaches are discussed. A simple numerical solution of Poissons equation for a stack of dielectric slabs based on a transfer matrix method is developed, enabling the calculation of the electron-hole interaction potential at very low computational cost and with reasonable accuracy. Using different potential models, direct and indirect exciton binding energies in these systems are calculated within Wannier-Mott theory, and a comparison of theoretical results with recent experiments on excitons in two-dimensional materials is discussed.