https://doi.org/10.1140/epjp/s13360-024-05613-1
Regular Article
Electronic excitation-induced amorphization in GaN and β-Ga2O3: an ab initio molecular dynamics study
1
School of Materials Science and Engineering, Anhui University, 230601, Hefei, China
2
Stony Brook Institute at Anhui University, Anhui University, 230601, Hefei, China
3
Institute of Physical Science and Information Technology, Anhui University, 230601, Hefei, China
4
Department of Materials Science and Engineering, University of Toronto, M5S 3E4, Ontario, Canada
5
Department of Mechanical and Industrial Engineering, University of Toronto, M5S 3G8, Ontario, Canada
c
21131@ahu.edu.cn
d
chandraveer.singh@utoronto.ca
Received:
28
May
2024
Accepted:
3
September
2024
Published online:
16
September
2024
In the present study, an ab initio molecular dynamics (AIMD) method is employed to explore the effect of electronic excitation on the microstructural evolution in GaN and β-Ga2O3. The AIMD results indicate that GaN and β-Ga2O3 undergo crystalline-to-amorphous phase transition under electron excitation conditions. At 300 K, the determined threshold electronic excitation concentration (ec) for GaN and β-Ga2O3 is 2.80% and 3.60%, respectively. The AIMD simulations have indicated that electronic excitation contributes to irradiation-induced crystalline-to-amorphous transition in GaN and β-Ga2O3, and the threshold ec of β-Ga2O3 is higher than that of GaN, which also confirms that the radiation tolerance of β-Ga2O3 is better than that of GaN under irradiation environments. It is noted that the mean square displacements (MSDs) of N and O atoms are larger than that of Ga atoms, which can be attributed to the fact that Ga atoms have a larger atomic mass compared to N and O atoms. Consequently, the displacement of N and O atoms primarily drives the structural amorphization of GaN and β-Ga2O3, respectively. It is further confirmed that the electronic excitation-induced amorphization is a solid–solid transition rather than a solid–liquid transition. The results of bond length and Bader charge both suggest that the interactions between Ga and O atoms are stronger than those between Ga and N atoms, which may contribute to the better radiation tolerance of β-Ga2O3. The AIMD results suggest that electronic excitation could play a significant role in the structural amorphization of semiconductors under low- or medium-energy electron and ion irradiation and advance the fundamental understanding of the radiation resistance of semiconductor materials.
Yan Zhou and Shuo Song have equally contributed to this work.
Copyright comment Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
