Geometric and electronic structures of monolayer hexagonal boron nitride with multi-vacancy

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Hexagonal boron nitride (h-BN) is an insulator with high thermal stability.
• Research has focused on h-BN's thermal properties over its electrical characteristics.
• Understanding h-BN's electrical behavior is crucial for advanced applications.

Purpose of the Study:

• To investigate the impact of vacancy defects on the electronic structure of monolayer h-BN.
• To explore how different vacancy configurations influence h-BN's geometric and electronic properties.
• To determine the conditions under which h-BN can become electrically conductive.

Main Methods:

• Computational calculations were performed on monolayer h-BN with mono- to tri-vacancy defects.
• Geometric deformation and electronic structure changes were analyzed.
• Formation energies of various vacancy defects were calculated.

Main Results:

• Vacancy defects induce geometric distortion in the h-BN lattice.
• New energy states appear between the valence and conduction bands, shifting the Fermi level.
• Boron atoms near vacancies attract, while nitrogen atoms repel.
• Multi-vacancy defects with more boron vacancies have lower formation energies.

Conclusions:

• Vacancy defects significantly alter the electronic structure of monolayer h-BN.
• The presence of multi-vacancies, especially those rich in boron vacancies, can render h-BN electrically conductive.
• These findings open possibilities for tuning h-BN's electrical properties through defect engineering.