B₅N₃ and B₇N₅ Monolayers with High Carrier Mobility and Excellent Optical Performance.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Two-dimensional (2D) materials beyond graphene and hexagonal boron nitride (h-BN) are of significant research interest.
• Predicting novel 2D materials with desirable electronic and optical properties remains a challenge.

Purpose of the Study:

• To computationally predict and characterize new 2D boron-nitrogen (B-N) compounds.
• To identify B-N monolayers with potential for experimental synthesis and practical applications.

Main Methods:

• Utilized an ab initio evolutionary search algorithm integrated with density functional theory (DFT) calculations.
• Investigated the formation enthalpy, dynamic stability, electronic structure, and optical properties of predicted 2D B-N materials.

Main Results:

• Identified B5N3 and B7N5 monolayers with low formation enthalpy and excellent dynamic stability, suggesting synthetic feasibility.
• B5N3 and B7N5 exhibit tunable indirect (1.99 eV) and direct (2.40 eV) band gaps, respectively.
• These materials show enhanced visible light absorption compared to 2D h-BN and possess high electron carrier mobilities.

Conclusions:

• B5N3 and B7N5 monolayers are promising candidates for experimental synthesis due to their stability and low formation energy.
• Their electronic and optical properties, including narrow band gaps and high carrier mobility, make them suitable for advanced electronics.
• These novel 2D B-N materials offer potential for efficient, environmentally benign solar energy conversion applications.