Crystal structure prediction of three- and two-dimensional Ga₂O₃ using a multi-objective differential evolution...

Area of Science:

• Condensed matter physics
• Materials science
• Computational materials science

Background:

• Gallium oxide (Ga2O3) is a wide-band-gap semiconductor with significant potential for high-power electronics and deep-ultraviolet optoelectronics.
• Predicting stable crystal structures is crucial for understanding and utilizing novel materials.

Purpose of the Study:

• To predict and screen novel three-dimensional (3D) and two-dimensional (2D) gallium oxide (Ga2O3) crystal structures.
• To evaluate the stability and electronic/optical properties of predicted Ga2O3 structures.

Main Methods:

• Utilized a multi-objective differential evolution algorithm combined with density functional theory (DFT) calculations.
• Predicted 11 3D and 4 2D Ga2O3 structures.
• Assessed structural stability through parameters, phonon spectra, elastic constants, and moduli.

Main Results:

• Successfully predicted 15 novel Ga2O3 structures.
• Identified two low-energy 3D structures matching known β-Ga2O3 and α-Ga2O3 phases, confirming their stability.
• Determined that both stable 3D and 2D Ga2O3 structures possess wide band gaps and favorable optical properties.

Conclusions:

• The study provides theoretical validation for the stability of predicted Ga2O3 structures.
• The findings offer crucial insights for the rational design of Ga2O3-based materials.
• These results guide the application of Ga2O3 in advanced microelectronic and photoelectric devices.