defects in metal dichalcogenides for optoelectronic applications.'
author:
- 'Haining Wang, Jared H. Strait, Changjian Zhang, Weimin Chan, Christina Manolatou, Sandip Tiwari, Farhan Rana'
title: Fast Exciton Annihilation by Capture of Electrons or Holes by Defects via Auger Scattering in Monolayer Metal Dichalcogenides
---

Introduction
============

Many body interactions play an important role in determining the electronic and optoelectronic properties of two-dimensional (2D) transition metal dichalcogenides (TMDs). The exciton binding energies in 2D chalcogenides are almost an order of magnitude larger compared to other bulk semiconductors [@Fai10; @Xu13; @Changjian14; @timothy; @Chernikov14]. The strong Coulomb interactions and small exciton radii in 2D-TMDs result in large optical oscillator strengths [@Changjian14; @Konabe14; @Berg14] and short radiative lifetimes [@Wanga14]. In this paper we show that the same factors also result in very fast capture of electrons and holes of excitons by defects from Auger processes leading to fast non-radiative recombination rates. The basic idea can be understood as follows. Consider the Auger process in which a hole (in the valence band) scatters off an electron (in the conduction band) and is captured by a mid-gap defect level and the electron (in the conduction band) takes the energy released in the hole capture process. In 