Unveiling and controlling the electronic structure of oxidized semiconductor surfaces: Crystalline oxidized InSb(100)(1 x 2)-O
Författare
Summary, in English
The exothermic nature of oxidation causes nearly all semiconductor applications in various fields like electronics, medicine, photonics, and sensor technology to acquire an oxidized semiconductor surface part during the application manufacturing. The significance of understanding and controlling the atomic scale properties of oxidized semiconductor surfaces is expected to increase even further with the development of nanoscale semiconductor crystals. The nature of oxidized semiconductor layers is, however, hard to predict and characterize as they are usually buried and amorphous. To shed light on these issues, we pursue a different approach based on oxidized III-V semiconductor layers that are crystalline. We present a comprehensive characterization of oxidized crystalline InSb(100)(1 x 2)-O layers by ab initio calculations, photoelectron spectroscopy, scanning tunneling microscopy, and spectroscopy, and demonstrate the electronic band structures of different oxidized phases of the semiconductor, which elucidate the previous contradictory semiconductor-oxidation effects. At 0.5 monolayer (ML) oxidation, oxygen atoms tend to occupy subsurface Sb sites, leading to metallic states in the semiconductor band gap, which arise from top dimers. When the oxidation is increased to the 1.0-2.0 ML concentration, oxygen occupies also interstitial sites, and the insulating band structure without gap states is stabilized with unusual occupied In dangling bonds. In contrast, the 2.5-3.0 ML oxide phases undergo significant changes toward a less ordered structure. The findings suggest a methodology for manipulating the electronic structure of oxidized semiconductor layers.
Avdelning/ar
Publiceringsår
2014
Språk
Engelska
Publikation/Tidskrift/Serie
Physical Review B (Condensed Matter and Materials Physics)
Volym
90
Issue
4
Dokumenttyp
Artikel i tidskrift
Förlag
American Physical Society
Ämne
- Physical Sciences
- Natural Sciences
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1098-0121