Individual Zn acceptors in the GaAs (110) surface layer are studied with a scanning tunneling microscope. Tunneling spectroscopy reveals a peak associated with a Zn acceptor state, whose linewidth and response to local band bending depend on proximity to neighboring subsurface Zn acceptors. Though identical in topographic images, surface-layer Zn with nearby subsurface neighbors exhibits a broad peak that is insensitive to band bending, while more isolated surface-layer Zn exhibit a narrow peak which is sensitive to band bending. These results are suggestive of a shallow-to-deep acceptor transition, driven by the random dopant distribution.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)