Charge-separated electron-hole liquid in transition metal dichalcogenide heterostructures

TL;DR

This paper explores the formation of charge-separated electron-hole liquids in transition metal dichalcogenide heterostructures, emphasizing the role of conduction band valleys and providing analytical insights into exciton binding and recombination.

Contribution

It introduces conditions for electron-hole liquid formation in TMD heterostructures and derives analytical formulas for exciton binding energy and recombination line shape.

Findings

Additional conduction band valleys are necessary for electron-hole liquid formation.

The binding energy of interlayer excitons is calculated using the variation method.

An analytical expression for the recombination line shape is provided.

Abstract

The possibility of the formation of an electron-hole liquid in the type II heterostructures based on monolayers (bilayers) of transition metal dichalcogenides is considered. It is indicated that additional valleys in the conduction band, which are present in bilayers, are required for its observation. The binding energy of the interlayer exciton is found by the variation method. An analytical formula is found for the shape of the recombination line of the electron-hole liquid.