Research On Radiation Damage Mechanism Of Wide Band Gap Semiconductor GaN

As one of the third generation semiconductor materials,gallium nitride(GaN)materials have excellent optical,physical and chemical properties,in addition to outstanding heat and radiation resistance,so GaN materials have a wide range of applications in many fields.In particular,the space environment or reactor environment,due to the presence of a large number of irradiation rays,irradiation rays will cause a certain degree of irradiation damage to GaN semiconductor materials,will produce lattice defects or elemental transmutation within the material,these will affect the size,shape,properties,quality and yield strength of the material changes.Therefore,the study of damage to GaN semiconductor materials under radiation irradiation is of great value.With the development and progress of science and technology,experimental methods can better reveal the irradiation damage characteristics of semiconductor materials,but due to the limitations of experimental equipment in observing the entire irradiation process,irradiation experiments alone cannot reflect the details of the interaction between irradiation rays and target materials,nor can they be used to analyse the causes of these defects,and because the experimental period is generally long The high cost of the experiments is also a major obstacle to experimental research.Therefore,computer simulations are essential for the study of material irradiation damage performance.In this paper,the damage effect of GaN materials under different irradiation is investigated based on the molecular dynamics(MD)method to reveal the irradiation damage mechanism of these materials.In this paper,we firstly investigate the damage effect of GaN material displacement under neutron irradiation.The damage effects produced by different PKA types are compared to analyse the extent of damage caused by different neutron energies.The analysis of the variation in the number of defects,the size and distribution of defect clusters and the calculation of the non-ionisation energy loss at different neutron energies shows that Ga PKA causes more severe damage than N PKA and produces larger defect clusters at deeper locations,which are not easily repaired.As the neutron energy increases,the displacement damage in GaN increases and the defect clusters become deeper with increasing energy,so the self-repair capability of GaN decreases with increasing energy.In addition,this paper investigates the displacement damage effect of GaN materials under α-particle irradiation.The cascade collisions caused by a single alpha particle at different energies are simulated and analysed.The damage effect of cumulative injection of multiple alpha particles into GaN materials at different injection rates is also investigated.In addition to the analysis of the number and type of defects and defect clusters,the radial distribution function and the identification of the internal crystal structure of the material are also investigated and analysed.The results show that under single alpha particle injection,the damage effect increases with increasing energy and the self-healing ability of the material decreases.Under multiple alpha particle injections,the material structure changes and the localised amorphous regions become larger and more numerous,while the self-healing ability of the material largely fails.