Unveiling Defect Dynamics in Gallium Oxide: In-Situ TEM Insights under Ion Irradiation and Annealing

Area of Science:

• Materials Science
• Semiconductor Physics
• Nanotechnology

Background:

• Gallium oxide (Ga2O3) possesses ultrawide bandgap and high breakdown field properties.
• Its transparency and robustness make it suitable for sensors in harsh environments.
• Understanding defect evolution is crucial for Ga2O3 device reliability.

Purpose of the Study:

• To investigate defect dynamics in Ga2O3 under ion irradiation and annealing.
• To observe defect evolution in real-time using in situ transmission electron microscopy (TEM).
• To analyze the combined effects of irradiation and temperature on Ga2O3.

Main Methods:

• In situ and ex situ transmission electron microscopy (TEM) for real-time defect observation.
• Ion irradiation (Kr2+) up to 15.4 displacements per atom (dpa) at room temperature.
• Annealing experiments from 100 °C to 500 °C, and simultaneous irradiation/annealing.

Main Results:

• Formation and growth of small black defects (SBDs), defect clusters, and dislocation networks under irradiation.
• Crystal structure stability during gradual heating, but accelerated defect evolution under combined stress.
• Observation of a β to γ phase transition during irradiation-only experiments.

Conclusions:

• In situ TEM provides critical insights into Ga2O3 defect behavior under extreme conditions.
• Combined irradiation and annealing significantly accelerate defect evolution.
• Findings aid in developing more resilient Ga2O3 electronic devices for demanding applications.