Excitonic effects in two-dimensional semiconductors: Path integral Monte Carlo approach

TL;DR

This paper uses Path Integral Monte Carlo to study excitonic effects in 2D semiconductors, providing detailed binding energies of excitons, trions, and biexcitons under various screening conditions, aiding experimental and theoretical research.

Contribution

It introduces a numerical approach to accurately calculate multi-carrier bound states in 2D semiconductors, including their dependence on dielectric screening.

Findings

Binding energies vary with dielectric screening strength.

Results cover both strong and weak screening regimes.

Data can benchmark future theoretical and experimental studies.

Abstract

One of the most striking features of novel 2D semiconductors (e.g., transition metal dichalcogenide monolayers or phosphorene) is a strong Coulomb interaction between charge carriers resulting in large excitonic effects. In particular, this leads to the formation of multi-carrier bound states upon photoexcitation (e.g., excitons, trions and biexcitons), which could remain stable at near-room temperatures and contribute significantly to optical properties of such materials. In the present work we have used the Path Integral Monte Carlo methodology to numerically study properties of multi-carrier bound states in 2D semiconductors. Specifically, we have accurately investigated and tabulated the dependence of single exciton, trion and biexciton binding energies on the strength of dielectric screening, including the limiting cases of very strong and very weak screening. The results of this work are potentially useful in the analysis of experimental data and benchmarking of theoretical and computational models.