Exciton-defect interaction and optical properties from a first-principles T-matrix approach

TL;DR

This paper introduces a first-principles T-matrix method to accurately simulate exciton-defect interactions and optical spectra in disordered 2D materials like monolayer MoS2, aligning well with experimental results.

Contribution

It develops a computationally efficient first-principles framework using the T-matrix approach to study exciton-defect interactions in 2D materials.

Findings

Accurately captures exciton-defect bound states.

Reproduces experimental photoluminescence spectra.

Provides a scalable method for disordered materials.

Abstract

Understanding exciton-defect interactions is critical for optimizing optoelectronic and quantum information applications in many materials. However, ab initio simulations of material properties with defects are often limited to high defect density. Here, we study effects of exciton-defect interactions on optical absorption and photoluminescence spectra in monolayer MoS2 using a first-principles T-matrix approach. We demonstrate that exciton-defect bound states can be captured by the disorder-averaged Green's function with the T-matrix approximation and further analyze their optical properties. Our approach yields photoluminescence spectra in good agreement with experiments and provides a new, computationally efficient framework for simulating optical properties of disordered 2D materials from first-principles.