|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||Algorithm Development in Materials Science and Engineering
||Unraveling Exciton Dynamics in 2D Van der Waals Heterostructures
||Junyi Liu, Xu Zhang, Gang Lu
|On-Site Speaker (Planned)
2D vdW heterostructures offer a fascinating platform to pursue fundamental science and device applications. Owing to reduced dielectric screening, excitonic effect is prominent in 2D materials. Recent experiments have revealed ultrafast charge transfer dynamics in transition metal dichalcogenides heterostructures, which is surprising giving the strong electron-hole binding of the excitons. Most theoretical calculations were performed based on local and semi-local exchange-correlation functionals, thus cannot capture the excitonic effect accurately. I will introduce a first-principles method that combines non-adiabatic molecular dynamics with linear-response time-dependent density functional theory. The method is formulated in planewave bases and pseudopotentials with range-separated hybrid functionals. As a result, the method can capture the excitonic effect accurately in extended 2D heterostructures. Using this method, we can shed light on the ultrafast charge transfer dynamics in vdW heterostructures and elucidate the role of “hot” excitons in promoting ultrafast charge transfer despite the momentum mismatch in twisted heterostructures.
||Planned: Supplemental Proceedings volume