Fermi Liquid Theory Sheds Light on "Hot" EHL in 1L-MoS${}_2$

Abstract

2D transition metal dichalcogenides (TMDCs) exhibit an electron-hole liquid phase transition at unusually high temperatures. Because these materials are atomically thin, optical excitation leads to material expansion. As a result, during the EHL phase transition the electronic band structure evolves due to both material thermal expansion and renormalization of the bands under high excitation densities. Specifically, these effects lead to indirect gap electronic band structure with a valence band maximum located at the $\Gamma$ valley. In this work we developed a methodology for analyzing the spectral evolution of the photoluminescence of suspended 1L-MoS${}_2$ during the EHL phase transition by using Fermi liquid theory. The resulting analysis reveals valley-specific carrier densities, radiative recombination efficiencies, and intraband carrier relaxation kinetics in 1L-MoS${}_2$. More broadly, the results outline a methodology for predicting critical EHL parameters, shedding light onto the EHL phase transition in 2D TDMCs.

13 pages, 4 figures, RevTex-4.2

References in corpus (6)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Electrical suppression of all nonradiative recombination pathways in monolayer semiconductors
• Theoretical phase diagram for the room temperature Electron-Hole Liquid in photo-excited quasi-2D monolayer MoS${}_2$

Cited by in corpus (1)

• Ultrafast Phonon-Diffuse Scattering as a Tool for Observing Chiral Phonons in Monolayer Hexagonal Lattices