  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.
