Localized electronic states around stacking faults in silicon carbide
2002 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, Vol. 65, no 3Article in journal (Refereed) Published
We report on a first-principles study of all the structurally different stacking faults that can be introduced by elide along the (0001) basal plane in 3C-, 4H-, and 6H-SiC based on the local-density approximation within the density-functional theory. Our band-structure calculations have revealed that both types of stacking faults in 4H-SiC and two of the three different types of stacking faults in 6H-SiC give rise to quasi-two-dimensional energy band states in the band gap at around 0.2 eV below the lowest conduction band, thus being electrically active in n-type material. Although stacking faults, unlike point defects and surfaces, are not associated with broken or chemically perturbed bonds, we find a strong localization, within roughly 10-15 Angstrom perpendicular to the stacking fault plane, of the stacking fault gap state wave functions. We find that this quantum-well-like feature of certain stacking faults in SiC can be understood in terms of the large conduction-band offsets between the cubic and hexagonal polytypes. Recent experimental results give qualitative support to our results.
Place, publisher, year, edition, pages
2002. Vol. 65, no 3
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-47907DOI: 10.1103/PhysRevB.65.033203OAI: oai:DiVA.org:liu-47907DiVA: diva2:268803