# Exciton-Defect Interaction and Optical Properties from a First-Principles T‑Matrix Approach

## TL;DR

This paper introduces a new method to study how defects affect the optical properties of 2D materials like MoS2, improving simulations for optoelectronic and quantum applications.

## Contribution

A first-principles T-matrix approach is developed to efficiently simulate optical properties of disordered 2D materials.

## Key findings

- Exciton-defect bound states are captured using the disorder-averaged Green’s function with T-matrix approximation.
- The method produces photoluminescence spectra matching experimental results for monolayer MoS2.
- The approach offers a computationally efficient framework for simulating optical properties in disordered 2D 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.