Role of defects in ultrafast charge recombination in monolayer <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>MoS</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>
Raquel Esteban-Puyuelo, Biplab Sanyal
Abstract
In this paper, we have systematically studied the role of point defects in the recombination time of monolayer ${\mathrm{MoS}}_{2}$ using time-dependent ab initio nonadiabatic molecular dynamics simulations. Various types of point defects, such as S vacancy, S interstitial, Mo vacancy, and Mo interstitial have been considered. We show that defects strongly accelerate the electron-hole recombination, especially interstitial S atoms do that by three orders of magnitude higher compared to pristine ${\mathrm{MoS}}_{2}$. Mo defects (both vacancy and interstitial) introduce a multitude of de-excitation pathways via various defect levels in the energy gap. The results of this study provide some fundamental understanding of photoinduced de-excitation dynamics in presence of defects in highly technologically relevant 2D ${\mathrm{MoS}}_{2}$.