Doping Tunable CDW Phase Transition in Bulk 1T-ZrSe$_2$

TL;DR

This study uses scanning tunnelling microscopy and spectroscopy to show how doping induces a charge density wave in bulk 1T-ZrSe$_2$, revealing local electronic changes and phase transition mechanisms.

Contribution

It provides the first local microscopic evidence linking doping-induced Fermi level shifts to CDW formation in bulk 1T-ZrSe$_2$, enhancing understanding of phase transitions in TMDs.

Findings

Doping shifts Fermi level into conduction band triggers CDW.

Atomic impurities induce local CDW reconstruction.

Gap opening at Fermi level associated with CDW transition.

Abstract

Tuneable electronic properties in transition metal dichalcogenides (TMDs) are essential to further their use in device applications. Here, we present a comprehensive scanning tunnelling microscopy and spectroscopy study of a doping-induced charge density wave (CDW) in semiconducting bulk 1T-ZrSe$_2$. We find that atomic impurities which locally shift the Fermi level ($E_F$) into the conduction band trigger a CDW reconstruction concomitantly to the opening of a gap at $E_F$. Our findings shed new light on earlier photoemission spectroscopy and theoretical studies of bulk 1T-ZrSe$_2$, and provide a local understanding of the electron-doping mediated CDW transition observed in semiconducting TMDs.