First-principles calculations of point defect migration mechanisms in InP

As an important second-generation semiconductor material, indium phosphide (InP) possesses excellent advantages such as a wide bandgap, high electron mobility, high photoelectric conversion efficiency, and strong radiation resistance. It is considered an excellent material for electronic devices in aerospace applications. However, point defects generated by space radiation particles in InP electronic devices can cause their electrical performance to degrade severely. In this study, first-principles calculations are employed to investigate the stable structures of point defects in InP and calculate the migration energy values of nearest-neighbor defects. Four stable structures of In vacancies and three stable structures of P vacancies are identified by constructing the stable structures of point defects in different charge states. The migration process of vacancy defects is studied, revealing that the migration energy of P vacancies is higher than that of In vacancies. Moreover, charged vacancy defects exhibit higher migration energy values than neutral vacancies. Regarding the migration process of interstitial defects, it is found that the migration energy of interstitial defects is smaller than that of vacancy defects. In the calculation of In interstitial migration process with different charge states, two different migration processes are found. Besides, during the migration calculations of P interstitial, a special intermediate state is discovered, resulting in multiple paths migrating to the nearest-neighbor position in the migration energy barrier diagram. The research results are helpful to understand the formation mechanism and migration behavior of defects in InP materials, and are important in designing and manufacturing InP devices with long-term stable operation in space environment.