Structural morphology and surface recrystallization properties of GaN nanoparticles with different sizes during sintering

LL Liu and TH Gao and Y Gao and YT Liu and Q Chen and YC Liang and Q Xie and QQ Xiao, CERAMICS INTERNATIONAL, 49, 32292-32300 (2023).

DOI: 10.1016/j.ceramint.2023.07.205

GaN is a promising third-generation semiconductor material for fabricating nanodevices with nanoscale dimensions. In particular, thick- film sensors fabricated with GaN nanoparticles (NPs) have good gas- sensing characteristics. This study used molecular dynamics simulation to investigate the effect of temperature and size on the structural morphology and surface recrystallization of GaN NPs during sintering. The diffusion behavior and changes in the structural morphology of atoms were analyzed based on the shrinkage ratio, mean square displacement, potential energy, and other methods. The results show that during sintering, the surface of two GaN NPs experienced recrystallization, which expanded with increasing temperature; however, the obvious sintering phenomenon occurred at 3000 K. Interestingly, the surface recrystallization of NPs exhibited a lamellar structure formed through a specific stacking method of the crystal structure. However, when the size of one of the two NPs was reduced, the small NP rapidly melted and was induced to crystallize into a complete NP (having the same crystal orientation as the large NP) by the large NP. Moreover, NPs underwent rigid-body rotation and relative rotation during sintering; however, plastic deformation and dislocations resulting from rotation were only found in the neck of NPs of the same size. The study results provide valuable insights at the atomic scale regarding the sintering of GaN NPs and a useful reference for preparing and processing nanodevices.

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