Influence of Fluorine and Oxygen Adsorption on the Electronic Properties of the InAs(111)A-(2*2) Surface

Abstract

Atomic and electronic structures of the reconstructed InAs(111)A-(2*2) surface are studied within den-sity functional theory. The most stable adsorption positions of oxygen and fluorine on the surface are de-termined. Our calculations show that oxygen adsorption leads to appearance of electronic states in band gap and the structure of these surface states strongly depends on adsorption geometry. An increase of oxy-gen concentration and its coadsorption with fluorine leads to substantial structural changes in the surface and subsurface layers due to adsorbate penetration into semiconductor. Evolution of the electronic struc-ture upon oxygen and fluorine adsorption on the reconstructed InAs(111)A-(2*2) surface in dependence on adsorbate geometry is analyzed. It is shown that surface states induced by oxygen adsorption can be par-tially removed by fluorine, when it forms bonds with the surface indium atoms. The formation of the indi-um–fluorine or indium–oxygen bonds proceeds due to charge transfer from arsenic atoms to indium ones in the surface layers. The microscopic mechanism of fluorine influence on the interface states at InAs–oxides interface is suggested. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35298