Blue emission at atomically sharp 1D heterojunctions between graphene and h-BN

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Atomically sharp heterojunctions in 2D materials offer unique 1D functionalities.
• Graphene and hexagonal boron nitride (h-BN) lateral heterostructures are promising for exploring electronic, thermal, spin, and optoelectronic properties.
• Interfacial properties between metallic graphene and insulating h-BN remain underexplored.

Purpose of the Study:

• To demonstrate and characterize a blue-emitting atomic-resolved heterojunction between graphene and h-BN.
• To investigate the origin of the observed emission.
• To explore methods for enhancing the optoelectronic properties of such heterojunctions.

Main Methods:

• Controlled growth of graphene and h-BN lateral heterostructures.
• Atomic-resolution imaging and spectroscopy to characterize the heterojunctions.
• Fabrication of graphene quantum dot arrays embedded in h-BN monolayers.

Main Results:

• Demonstration of a blue-emitting atomic-resolved heterojunction between graphene and h-BN.
• Tentative attribution of the blue emission to localized energy states at disordered boundaries.
• Enhancement of blue emission by increasing interface density in graphene quantum dots within h-BN.

Conclusions:

• Atomically resolved heterojunctions in 2D materials are a viable platform for novel optoelectronic applications.
• Disordered interfaces in graphene-h-BN heterostructures can lead to unique optical properties.
• Engineering interface density offers a route to tune and enhance optoelectronic functionalities in 2D heterostructures.