Two-Dimensional TeB Structures with Anisotropic Carrier Mobility and Tunable Bandgap

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Two-dimensional (2D) semiconductors are crucial for next-generation electronics and optoelectronics due to their unique electronic and optical properties.
• Developing new 2D materials with tunable bandgaps and high carrier mobility remains a key research challenge.

Purpose of the Study:

• To computationally investigate the structural, electronic, and stability properties of novel two-dimensional tellurium boride (TeB) monolayers.
• To explore the potential of these TeB monolayers for electronic and optoelectronic applications.

Main Methods:

• Density Functional Theory (DFT) calculations were employed to study the electronic band structures.
• Particle swarm-intelligent global structure search was utilized to predict stable 2D TeB structures.
• Dynamical and thermal stability analyses were performed to assess experimental feasibility.

Main Results:

• Two stable 2D TeB monolayers, alpha-TeB and beta-TeB, were theoretically proposed.
• Both alpha-TeB and beta-TeB were identified as indirect bandgap semiconductors with bandgaps of 2.3 eV and 2.1 eV, respectively.
• The beta-TeB sheet demonstrated high hole mobility (6.90 × 10^2 cm^2 V^-1 s^-1).
• New horizontal and lateral heterostructures were identified, with the lateral heterostructure exhibiting a direct bandgap.

Conclusions:

• The proposed alpha-TeB and beta-TeB monolayers possess high stability, suggesting feasibility for experimental synthesis.
• Their semiconductor properties and high carrier mobility make them promising candidates for electronic and optoelectronic applications.
• The identified heterostructures, particularly the lateral one with a direct bandgap, open avenues for further exploration in device applications.