Epitaxial Growth and Band Structure of Te Film on Graphene

TL;DR

This study demonstrates the epitaxial growth of tellurium films on graphene, revealing their atomic structure and electronic band properties, with potential applications in electronics and optoelectronics.

Contribution

It provides new insights into the atomic arrangement and band structure of Te films grown on graphene via molecular beam epitaxy.

Findings

Te films are composed of parallel helical chains on graphene.

Band gap increases as Te film thickness decreases, reaching ~0.92 eV for monolayer.

Explicit band bending observed at the Te-graphene interface.

Abstract

Tellurium (Te) films with monolayer and few-layer thickness are obtained by molecular beam epitaxy on a graphene/6H-SiC(0001) substrate and investigated by in situ scanning tunneling microscopy and spectroscopy (STM/STS). We reveal that the Te films are composed of parallel-arranged helical Te chains flat-lying on the graphene surface, exposing the (1x1) facet of (10-10) of the bulk crystal. The band gap of Te films increases monotonically with decreasing thickness, reaching ~0.92 eV for the monolayer Te. An explicit band bending at the edge between the monolayer Te and graphene substrate is visualized. With the thickness controlled in atomic scale, Te films show potential applications of in electronics and optoelectronics.