Defect states at Ill-V semiconductor oxide interfaces

摘要

Models of insulating interfaces between (100)GaAs and HfO_2, Gd_2O_3, and Al_2O_3 are constructed and used to host various interfacial defects to see which give rise to gap states. The antibonding state of As-As dimers is found to lie in the upper band gap and is identified as a possible major source of the interface gap states which cause Fermi level pinning in GaAs-oxide interfaces and field effect transistors.