Hexagonal Boron Nitride Coated Carbon Nanotubes: Interlayer Polarization Improved Field Emission

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Carbon nanotubes (CNTs) are widely studied for field emission applications.
• Hexagonal boron nitride (h-BN) is known for its unique electronic and insulating properties.
• Interface engineering is crucial for optimizing nanomaterial-based devices.

Purpose of the Study:

• To investigate the effects of h-BN coating on CNTs for field emission.
• To understand the charge dynamics and polarization at the h-BN/CNT interface.
• To evaluate the stability and performance of h-BN coated CNTs in field emission.

Main Methods:

• Coating of CNTs with h-BN.
• Analysis of interface polarization using electronic structure calculations.
• Field emission measurements to assess stability and current density.
• Investigation of charge transfer mechanisms.

Main Results:

• h-BN coating on CNTs induces significant interface polarization, localizing charges at Nitrogen (N) and Carbon (C) atoms.
• Field emission from coated tubes demonstrates high stability with current density fluctuations within 4%.
• An electric field at the interface facilitates charge transfer.
• Electron emission occurs via occupied and unoccupied bands of N and Boron (B) atoms.

Conclusions:

• h-BN coating effectively enhances the field emission properties of CNTs.
• Interface polarization and controlled charge transfer are key to stable electron emission.
• The findings suggest potential for h-BN/CNT composites in advanced electron sources.