# Structural and electronic properties of germanene on MoS$_2$

## TL;DR

This paper reports the successful synthesis of germanene on MoS₂, a band gap material, and investigates its structural and electronic properties, revealing unique band features through experiments and calculations.

## Contribution

It demonstrates the growth of germanene on a non-metallic substrate and analyzes its electronic structure, which is a novel approach compared to previous metallic substrate methods.

## Key findings

- Germanene successfully synthesized on MoS₂ surface.
- Lattice constant of germanene is about 20% larger than MoS₂.
- Electronic structure includes linearly dispersing and parabolic bands crossing the Fermi level.

## Abstract

To date, germanene has only been synthesized on metallic substrates. A metallic substrate is usually detrimental for the two-dimensional Dirac nature of germanene because the important electronic states near the Fermi level of germanene can hybridize with the electronic states of the metallic substrate. Here we report the successful synthesis of germanene on molybdenum disulfide (MoS$_2$), a band gap material. Pre-existing defects in the MoS$_2$ surface act as preferential nucleation sites for the germanene islands. The lattice constant of the germanene layer (3.8 $\pm$ 0.2 \AA) is about 20\% larger than the lattice constant of the MoS$_2$ substrate (3.16 \AA). Scanning tunneling spectroscopy measurements and density functional theory calculations reveal that there are, besides the linearly dispersing bands at the $K$ points, two parabolic bands that cross the Fermi level at the $\Gamma$ point.