Numerical simulation of the primary displacement damage in GaAs_1-xN_x with low nitrogen atomic content

Molecular dynamics (MD) simulation is conducted to investigate the primary displacement damage of GaAs1-xNx as a function of nitrogen atoms (N) composition x (0-0.2), where the primary knock-on atom (PKA) energy is within 10 keV. The evolution process of Frenkel pairs is similar to that of antisites. The results show that higher x increases the cascade parameters of Frenkel pairs including the thermal peak number (NFp), thermal peak time (tFp), and stable time (tFs) while decreasing the stable number (NFs). The recombine efficiency and threshold displacement energy (Ed) increase with increasing the composition x of nitrogen atoms is observed. Meanwhile, due to the existence of various antisites, there are differences between the number of vacancies and interstitials for the same element. During this change, the surviving number of Ga defects is more susceptible to be influenced. As to clusters, the fraction of clusters for vacancies is larger than that for interstitials, while the distribution of interstitials concentrates on point defects. Finally, it is found that point defects and small clusters are the main reduction objects as composition x increases.