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A combined AIMD and DFT study of the low-energy radiation responses of GaN.
Jiang, Ming; Cheng, Nuo; Zhu, Xin-Yu; Hu, Xuan-Liang; Wang, Zi-Han; Liu, Ning; Song, Shuo; Wang, Sheng-Ze; Liu, Xu-Sheng; Singh, Chandra Veer.
Afiliación
  • Jiang M; Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China. 21131@ahu.edu.cn.
  • Cheng N; School of Materials Science and Engineering, Anhui University, Hefei, 230601, China.
  • Zhu XY; School of Materials Science and Engineering, Anhui University, Hefei, 230601, China.
  • Hu XL; Stony Brook Institute at Anhui University, Anhui University, Hefei 230601, China.
  • Wang ZH; Stony Brook Institute at Anhui University, Anhui University, Hefei 230601, China.
  • Liu N; Stony Brook Institute at Anhui University, Anhui University, Hefei 230601, China.
  • Song S; Stony Brook Institute at Anhui University, Anhui University, Hefei 230601, China.
  • Wang SZ; Stony Brook Institute at Anhui University, Anhui University, Hefei 230601, China.
  • Liu XS; College of Physics and Engineering Technology, Chengdu Normal University, Chengdu 611130, China. xsliu999@126.com.
  • Singh CV; Department of Materials Science and Engineering, University of Toronto, 184 College Street, Suite 140, Toronto, ON M5S 3E4, Canada. chandraveer.singh@utoronto.ca.
Phys Chem Chem Phys ; 26(24): 17383-17395, 2024 Jun 19.
Article en En | MEDLINE | ID: mdl-38860766
ABSTRACT
Although GaN is a promising candidate for semiconductor devices, degradation of GaN-based device performance may occur when the device is bombarded by high-energy charged particles during its application in aerospace, astronomy, and nuclear-related areas. It is thus of great significance to explore the influence of irradiation on the microstructure and electronic properties of GaN and to reveal the internal relationship between the damage mechanisms and physical characteristics. Using a combined density functional theory (DFT) and ab initio molecular dynamics (AIMD) study, we explored the low-energy recoil events in GaN and the effects of point defects on GaN. The threshold displacement energies (Eds) significantly depend on the recoil directions and the primary knock-on atoms. Moreover, the Ed values for nitrogen atoms are smaller than those for gallium atoms, indicating that the displacement of nitrogen dominates under electron irradiation and the created defects are mainly nitrogen vacancies and interstitials. The formation energy of nitrogen vacancies and interstitials is smaller than that for gallium vacancies and interstitials, which is consistent with the AIMD results. Although the created defects improve the elastic compliance of GaN, these radiation damage states deteriorate its ability to resist external compression. Meanwhile, these point defects lead the Debye temperature to decrease and thus increase the thermal expansion coefficients of GaN. As for the electronic properties of defective GaN, the point defects have various effects, i.e., VN (N vacancy), Gaint (Ga interstitial), Nint (N interstitial), and GaN (Ga occupying the N lattice site) defects induce the metallicity, and NGa (N occupying the Ga lattice site) defects decrease the band gap. The presented results provide underlying mechanisms for defect generation in GaN, and advance the fundamental understanding of the radiation resistances of semiconductor materials.

Texto completo: 1 Bases de datos: MEDLINE Idioma: En Revista: Phys Chem Chem Phys Asunto de la revista: BIOFISICA / QUIMICA Año: 2024 Tipo del documento: Article País de afiliación: China

Texto completo: 1 Bases de datos: MEDLINE Idioma: En Revista: Phys Chem Chem Phys Asunto de la revista: BIOFISICA / QUIMICA Año: 2024 Tipo del documento: Article País de afiliación: China