Electronic states of Si nanostructures in a strong electric field: Bandgap ionization and Stark ladders

Nacir Tit, M. W.C. Dharma-Wardana

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


The electronic states of Si slabs contained within SiO2 barriers and placed in strong electric fields have been calculated using tight-binding theory. The SiO2 barriers resolve the problem of dangling bonds and surface termination in a simple and unobtrusive manner, and also relate to actual nanostructures. Two critical fields are identified from the calculations. The electronic density of states (DOS) change very slowly until the first critical field Fc1 begins to be reached. This first critical field at 7 MV cm-1 corresponds to the onset of the silicon-bandgap ionization, in excellent agreement with the vacuum emission experiments. The second critical field Fc2 is revealed by the clear fragmentation of the density of states into Wannier-Stark ladders. Our theoretical methods apply directly to Si/SiO2 and other superlattice structures as well. The field-dependent DOS results presented here are relevant to theories of electroluminescent devices, high-field hot-electron transport as well as to opto-electronic switching devices.

Original languageEnglish
Pages (from-to)330-333
Number of pages4
JournalSemiconductor Science and Technology
Issue number4
Publication statusPublished - Apr 2003
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry


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