Two-Dimensional Band Dispersion of Ultra-Flat Hexagonal Bismuthene Grown on Ag(111) Bulk and Quantum-Well Films

TL;DR

This study uses ARPES to analyze the electronic band structure of ultraflat hexagonal bismuthene grown on Ag(111), revealing its stability across different substrate thicknesses and confirming its similarity to previously reported structures.

Contribution

It provides direct experimental evidence of the band structure of ultraflat bismuthene on Ag(111) and shows its stability against substrate thickness variations.

Findings

The (2×2) superstructure can be grown at low temperatures.

The band structure remains unchanged with decreasing Ag layer thickness.

The superstructure transforms into a surface alloy at 300 K.

Abstract

Two-dimensional band dispersion of (2$\times$2) superstructure with Bi grown on Ag(111), which has been urged as an ultraflat hexagonal bismuthene, is investigated using angle-resolved photoemission spectroscopy (ARPES). The (2$\times$2)-Bi superstructure can be grown on the Ag(111) surface at low temperatures; it transforms into a surface alloy with a ($\sqrt{3}\times\sqrt{3}$) superstructure at 300 K. ARPES measurements reveal the consistency with the band structure of ultraflat bismuthene in previous reports. The band structure of (2$\times$2)-Bi surface remains unchanged with decreasing Ag layer thickness, indicating the limited penetration of Bi p-orbitals into the Ag layer.