Nucleation kinetics of twins in bulk β-Ga2O3 crystal

• Published in: Materials & design 2024-07, Vol.243, p.113012, Article 113012
• Main Authors: Wang, Pei, Li, Qi, Hou, Tong, Lin, Na, Jia, Zhitai, Zhao, Xian, Tao, Xutang, Mu, Wenxiang
• Format: Article
• Language: English
• Subjects: Crystal growth; Nucleation kinetics; Smooth interface; Twin boundaries
• ISSN: 0264-1275
• DOI: 10.1016/j.matdes.2024.113012

[Display omitted] •The average formation energy of twin-B in β-Ga2O3 is 6.67 mJ·m−2.•The (100)-B plane of β-Ga2O3 follows the smooth interface growth mode.•Significant supercooling is the primary driving force for the forming of twins.•The nucleus kinetics of twins in β-Ga2O3 is described for the first time. The twin boundary (TB) is a planar defect that both destroys the integrity of the crystal and significantly deteriorates the performance of semiconductor devices. However, limited research exists on the initial crystal nucleus kinetics of TB, which is a crucial aspect for a comprehensively understanding the twinning mechanism. Here, the nucleation kinetics process of TB has been thoroughly studied regarding crystal morphology, growth interface at the atomic scale, and first-principle calculations in β-Ga2O3. The nucleation kinetics process of TB originates from the smooth interface growth mode of (100)-B, which requires a significant degree of supercooling. During the crystal growth, the large degree of supercooling in front of the (100)-B plane at the three-phase boundary (TPB) leads to nucleation of TB. The twin type of β-Ga2O3 is recognized as twin-B among the two thermodynamically equivalent structures. It is a glide reflection twin whose glide process initiates with a 1/4 length of the [001] vector and then with a 1/2 length of the [010] vector. This study has developed the nucleation kinetics of TB, thus enriching the theory of crystal defects. The revealed relationship between TB and the smooth interface growth mode holds great significance for guiding the suppression of twins.