Metal vacancies, their complexes and clusters in nitride semiconductors (VACCINES)

The project aim is to find a link between the concentration of vacancies in GaN, InGaN, AlGaN and AlInGaN layers and technological parameters of metalorganic vapor phase epitaxy. Technological conditions for clustering of vacancies and binding of vacancies with other point defects will be defined. Variable energy positron annihilation spectroscopy will be employed as the main characterization method of vacancy-containing defects. Understanding of the relation between technological parameters of nitride epitaxy and vacancy concentration and clustering will be extremely important for technology improvement of nitride based devices and their lifetime. Identification of vacancy-containing defects and their concentration will help us to disclose the effect of particular native point defects, on optical and electrical properties of nitride layers and heterostructures. In addition, the phenomenon of positron-induced luminescence will be explored and developed into a real characterization method of defect-related luminescence.