MoS2 and Janus (MoSSe) based van der Waals heterostructures | Arunima Singh
Summary :
MoS2 monolayer, a prototypical transition metal dichalcogenide (TMD), with high carrier mobility and apt optical properties have often been used in photocatalysis. Janus (MoSSe) too follows the same. However, the usage of these monolayers is limited by the carrier (e- -h+) recombination, making it imperative to examine their bilayer van der Waals heterostructure (vdW HTS), where the spatial separation of e--h+ on two layers reduce recombination. The design of bilayer vdW HTSs here, consists of TMDs (HfS2, ZrS2, TiS2, WS2) and transition metal oxides (TMOs) (HfO2, T-SnO2, T-PtO2). The present work displays curiosity in their Z-scheme photocatalytic capability, where faster interlayer e--h+ recombination as compared to that of intralayer, is required for efficient spatial charge separation and hence, redox reactions. We have performed first-principles based calculations under the framework of (hybrid) density functional theory (DFT) and manybody perturbation theory (GW approximation), to obtain the band edge levels and optical spectra, respectively.
About Author :
Ms. Arunima Singh is pursuing Ph.D. in the Department of Physics, IIT Delhi since July 2018. She works in the field of 2D materials and van der Waals heterostructures (vdW HTSs). Her material designs aim to have significant impact in the environment. She uses first principles-based simulation for analyzing the same, by integrating different level of theories starting from state-of-the-art density functional theory (DFT) to highly sophisticated quantum chemistry methods (viz. GW, BSE, etc.). She has been interested in the probable point defects formed in MoS2 monolayer that can tune the band gap for feasible optoelectronic applications. Moreover, she has been working on MoS2 and MoSSe (Janus) based van der Waals heterostructures (vdW HTSs), for optoelectronic, photocatalytic and electrocatalytic applications.
