First-principles calculations of screw dislocations in β -Ga 2 O 3

Abstract Gallium oxide (Ga 2 O 3 ) is an ultra-wide bandgap semiconductor with excellent potential for high-power device applications. Some defects will inevitably occur during the growth of Ga 2 O 3 . Dislocations, as one of the main defects, have a significant impact on the mechanical and electrical properties of materials. In this work, dislocations in β -Ga 2 O 3 are systematically studied via first principles calculations, with a primary focus on the screw dislocation occurring on the ( 2 ¯ 01 ) plane with b = . The concept of Ga tetra -Ga octa -dislocation is proposed. The three dislocation core structures, Ga octa -O Ⅰ -Ga tetra -near-dislocation, Ga octa -O Ⅰ -Ga tetra -far-dislocation, and Ga octa -O Ⅲ -Ga octa -far-dislocation have been verified. The study find that the introduction of dislocations leads to a narrowing of the bandgap. This suggests that the presence of dislocations may reduce the breakdown voltage, radiation resistance, and other related properties of β -Ga 2 O 3 . This study provides a new perspective for the theoretical investigation of dislocations in β -Ga 2 O 3 , with significant guiding implications. It also reveals the impact of dislocations on the electrical properties of β -Ga 2 O 3 , laying a foundation for further research.