Manipulating Edge Current in Hexagonal Boron Nitride via Doping and Friction.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Hexagonal boron nitride (hBN) is typically an insulator, but its edges can exhibit unique electronic properties.
• Understanding edge conduction is crucial for developing novel electronic devices.

Purpose of the Study:

• To investigate and map electrical current at the stacking boundaries of pristine and doped hBN.
• To differentiate edge conduction from the insulating bulk properties of hBN.
• To explore the role of defects and heterostructures in modulating edge conductivity.

Main Methods:

• Conductive atomic force microscopy (CAFM) was used to map spatially correlated electrical current.
• Current-voltage (I-V) characteristics were analyzed using the Poole-Frenkel (PF) model.
• A phenomenological model was developed to explain conduction in multilayer graphene (MLG)/hBN heterostructures.

Main Results:

• Pristine hBN edges are insulating, while O-doped edges show significantly higher current.
• Nonlinear I-V characteristics in O-doped hBN suggest trap-assisted barrier lowering.
• Electron conduction was observed at buried pristine hBN edges in MLG/hBN heterostructures, contradicting theoretical predictions.
• A model involving surface charge localization and internal electric fields explained the observed conduction.

Conclusions:

• Defect engineering, specifically oxygen doping, can induce significant edge conductivity in hBN.
• Edge conduction in hBN heterostructures can be manipulated by controlling defect states and interface charges.
• These findings provide fundamental insights into insulatronics and the potential for 1D-2D synergized insulators.