Interaction between hydrogen and gallium vacancies in β-Ga₂O₃

Area of Science:

• Materials Science
• Computational Materials Science
• Semiconductor Physics

Background:

• Gallium vacancies in β-Ga₂O₃ can impact its electronic and optical properties.
• Understanding defect compensation mechanisms is crucial for optimizing β-Ga₂O₃ performance.

Purpose of the Study:

• Investigate the interaction between hydrogen and gallium vacancies in β-Ga₂O₃.
• Determine the stability and formation energies of hydrogen-gallium vacancy complexes.
• Elucidate the role of hydrogen concentration and vapor pressure on vacancy compensation.

Main Methods:

• Utilized the revised Heyd-Scuseria-Ernzerhof screened hybrid functional (HSE06) for calculations.
• Simulated hydrogen interactions with gallium vacancies at various concentrations.
• Computed formation energies and bonding characteristics of hydrogen-vacancy complexes.

Main Results:

• Hydrogen atoms can compensate gallium vacancies, forming stable complexes.
• A single gallium vacancy can bind up to four hydrogen atoms.
• Formation energies decrease with increasing hydrogen atoms, indicating enhanced stability.
• Hydrogen prefers binding to three-coordinated oxygen atoms.
• Complexes with more than two hydrogen atoms exhibit high stability and annealing temperatures.
• Vacancy concentrations increase with rising vapor pressures.

Conclusions:

• Hydrogen acts as an effective compensating agent for gallium vacancies in β-Ga₂O₃.
• The stability of hydrogen-vacancy complexes increases with higher hydrogen content.
• This study provides insights into hydrogen's impact on β-Ga₂O₃ defect properties.