Scanning tunneling microscopy and spectroscopy of the electronic structure of dislocations in GaN/Si(111) grown by molecular-beam epitaxy

摘要

By using cross-sectional scanning tunneling microscopy, a correlation between the surfacenmorphology and the corresponding electronic states of the dislocations terminated at the GaNu000111 ¯00u0002ncleavage surfaces grown by molecular-beam epitaxy has been demonstrated. Both scanningntunneling spectroscopy and analysis of the dislocations on electronic structures suggest that regionsnsurrounding dislocations register gap states in the fundamental band gap of GaN. Closely examiningnthe recognition of the electronic structure reveals that the defect levels could provide the possibilitynof yellow luminescence, involving a transition from the conduction-band edge to a level at 1.2 eV