By Topic

Surface-induced charge at a Ge (100) dimer surface and its interaction with vacancies and self-interstitials

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $31
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Kamiyama, Eiji ; Department of Communication Engineering, Okayama Prefectural University, 111 Kuboki, Soja, Okayama 719-1197, Japan ; Sueoka, Koji ; Vanhellemont, Jan

Your organization might have access to this article on the publisher's site. To check, click on this link: 

The behavior of intrinsic point defects near the Ge (100) surface was investigated by using ab initio calculations. A thin plate model with clean Ge surfaces including a dimer structure on both sides was examined. A decrease of the formation energies of both types of intrinsic point defects near the surface is obtained similar as was reported before for Si. An important difference, however, is that the impact of the electric charges at the Si surface vanishes around the fifth layer, while for Ge, the effect of negative charges near the surface remains and positive charges are observed even deeper than the fifteenth layer from the surface. In bulk Ge, negatively charged vacancies are reported to be stable. Opposite to this, the neighbouring atoms around a vacancy near the Ge surface have a strong positive charge, compared with the case of Si. Taking these facts into consideration, the difference of the charge state of a vacancy in the bulk and that near the surface can be explained by band bending due to the surface-induced charge. A self-interstitial in bulk Ge most likely has a positive charge state (+2 or +1). It is also shown that a self-interstitial except for the position in the second layer away from the surface is positively charged. This charging can lead to a reflection of self-interstitials by the Ge surface because of the repulsive force between the positive charges of surface atoms and those of self-interstitials. Such interstitial reflection was suggested to explain experimental diffusion observations when self-interstitials are generated inside a bulk crystal by knocking-on Ge atoms in an implantation or irradiation process during a thermal anneal.

Published in:

Journal of Applied Physics  (Volume:113 ,  Issue: 9 )