Ferroelectric surface induced electron doping in a zigzag graphene nanoribbon

Area of Science:

• Condensed Matter Physics
• Materials Science
• Surface Science

Background:

• Graphene nanoribbons (GNRs) exhibit unique electronic and magnetic properties.
• Ferroelectric materials offer tunable polarization for electronic device applications.
• The interface between GNRs and ferroelectrics is crucial for novel electronic functionalities.

Purpose of the Study:

• To investigate the electronic and magnetic properties of zigzag graphene nanoribbons (zGNRs) at the interface with ferroelectric PbTiO3 (001).
• To understand how the ferroelectric polarization influences the zGNR's doping, band gap, and magnetic state.
• To explore the role of ferroelectric surface features in tuning zGNR characteristics.

Main Methods:

• First-principles calculations were employed to simulate the zGNR/PbTiO3 interface.
• Both upward and downward ferroelectric polarization configurations were considered.
• The influence of atomic relaxation and electronic distribution at the interface was analyzed.

Main Results:

• Ferroelectric polarization direction dictates zGNR doping: downward polarization induces p-type doping, while upward polarization maintains intrinsic behavior.
• Surface ferroelectric polarization, atomic relaxation, and electronic distribution significantly tune zGNR properties.
• Polarization closes the zGNR band gap by weakening the magnetic moment of edge carbon atoms.
• The zGNR antiferromagnetic ground state and α-β degeneracy are preserved.

Conclusions:

• The interface between zGNRs and ferroelectric PbTiO3 offers a pathway to tune electronic and magnetic properties via electric polarization.
• Ferroelectric polarization can control the doping type and effectively close the band gap in zGNRs.
• This study highlights the potential for ferroelectric/2D material heterostructures in next-generation electronic devices.