Tuning the Charge Transfer of Transition Metal Dichalcogenides via Misfit Layer Compounds

TL;DR

This study demonstrates that misfit layer compounds can precisely tune electron doping in 2D NbSe2 monolayers, enabling controlled engineering of electronic states through stoichiometric variation.

Contribution

It introduces misfit layer compounds as a versatile platform for tuning the electronic properties of 2D transition metal dichalcogenides via chemical alloying.

Findings

La/Pb ratio controls Fermi level shift in NbSe2

Rocksalt layer acts as a universal electron donor

NbSe2 maintains 2D character within the heterostructure

Abstract

Misfit layer compounds (MLCs) are a versatile platform for exploring the electronic phase diagram of two dimensional (2D) materials beyond the limits of conventional gating techniques. This work demonstrates the precise tunability of electron doping in NbSe2 monolayers through chemical alloying within the rocksalt layer of (LaxPb1xSe)1.14(NbSe2)2 heterostructures. By combining first principles density functional theory (DFT) calculations with angle resolved photoemission spectroscopy (ARPES), we prove that the rocksalt unit acts as an universal electron donor. We show that varying the La Pb ratio results in a rigid Fermi level shift, still preserving the NbSe2 electronic structure. Crucially, photon energy dependent ARPES confirms that the NbSe2 layers nearly maintain their intrinsic 2D character and orbital identity within the three dimensional misfit. This study establishes MLCs as a reliable platform for engineering emergent states in 2D transition metal dichalcogenides through precise stoichiometric control.