Crystalline and electronic structure of single-layer TaS$_2$

TL;DR

This study investigates the crystalline and electronic properties of single-layer TaS$_2$ grown on Au(111), revealing its polymorph, doping level, and electronic structure, with no observed superconductivity or charge density waves at low temperatures.

Contribution

It provides detailed experimental and theoretical analysis of single-layer TaS$_2$, including its growth, structure, doping, and electronic properties, which were not previously characterized in this detail.

Findings

Single-layer TaS$_2$ adopts the 1H polymorph.

The material is strongly n-doped with 0.3 electrons per unit cell.

No superconductivity or charge density waves observed down to 4.7 K.

Abstract

Single-layer TaS$_2$ is epitaxially grown on Au(111) substrates. The resulting two-dimensional crystals adopt the 1H polymorph. The electronic structure is determined by angle-resolved photoemission spectroscopy and found to be in excellent agreement with density functional theory calculations. The single layer TaS$_2$ is found to be strongly n-doped, with a carrier concentration of 0.3(1) extra electrons per unit cell. No superconducting or charge density wave state is observed by scanning tunneling microscopy at temperatures down to 4.7 K.