Structural and Electronic Properties of Germanene on MoS_{2}

Area of Science:

• Materials Science
• Condensed Matter Physics
• Surface Science

Background:

• Germanene, a 2D material, has typically been synthesized on metallic substrates.
• Metallic substrates can disrupt the Dirac nature of germanene due to electronic state hybridization.

Purpose of the Study:

• To report the successful synthesis of germanene on a non-metallic substrate.
• To investigate the electronic properties of germanene on molybdenum disulfide (MoS_{2}).

Main Methods:

• Synthesis of germanene on molybdenum disulfide (MoS_{2}) using a band gap material.
• Utilizing scanning tunneling spectroscopy (STS) for electronic property analysis.
• Employing density functional theory (DFT) calculations for theoretical validation.

Main Results:

• Germanene was successfully synthesized on MoS_{2}, with defects acting as nucleation sites.
• The synthesized germanene layer exhibited a lattice constant of 3.8±0.2 Å, about 20% larger than MoS_{2}.
• STS and DFT revealed linearly dispersing bands at K points and two parabolic bands crossing the Fermi level at the Γ point.

Conclusions:

• Synthesis of germanene on a band gap material like MoS_{2} is feasible.
• This approach avoids detrimental hybridization with metallic substrates, preserving germanene's electronic properties.
• The electronic structure of germanene on MoS_{2} shows unique characteristics at the Γ point.