Structural Phase Transitions In A Mowse2 Monolayer: Molecular Dynamics Simulations And Variational Autoencoder Analysis

Electrical and optoelectronic properties of two-dimensional (2D) transition metal dichalcogenides (TMDCs) can be tuned by exploiting their structural phase transitions. Here semiconducting (2H) to metallic (1T) phase transition is investigated in a strained MoWSe2 monolayer using molecular dynamics (MD) simulations. Novel intermediate structures called alpha and beta are found between the 2H and 1T phases. These intermediate structures are similar to those observed in a 2D MoS2 by scanning transmission electron microscopy. A deep generative model, namely the variational autoencoder (VAE) trained by MD data, is used to generate novel heterostructures with alpha and beta interfaces. Quantum simulations based on density functional theory show that these heterostructures are stable and suitable for novel nanoelectronics applications.