Nanoelectronic Modeling Lecture 33: Alloy Disorder in Bulk

By Gerhard Klimeck1, Timothy Boykin2, Chris Bowen3

1. Electrical and Computer Engineering, Purdue University, West Lafayette, IN 2. Electrical and Computer Engineering, University of Alabama in Huntsville, Huntsville, AL 3. Lockheed Martin Advanced Technology Laboratories

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This presentation discusses disorder in AlGaAs unstrained systems in bulk.

  • Bandstructure of an ideal simple unit cell
  • What happens when there is disorder?
  • Concept of a supercell
  • Band folding in a supercell
  • Band extraction from the concept of approximate bandstructure
  • Comparison of alloy disorder with the virtual crystal approximation
  • Configuration noise, concentration noise
  • How large does an alloy supercell have to be? When does the “bulk” condition occur?

Learning Objectives:

  1. Bandedges and bandgaps are influenced by:
    1. Placement / configuration disorder
    2. Concentration noise
    3. Clustering
  2. System size is very important
    1. “bulk” starts at 100,000 atoms
    2. => Nanostructures are not “bulk”
      => like quantum dots, nanowires, and quantum wells vary locally

Cite this work

Researchers should cite this work as follows:

  • Gerhard Klimeck, Timothy Boykin, Chris Bowen (2010), "Nanoelectronic Modeling Lecture 33: Alloy Disorder in Bulk,"

    BibTex | EndNote



Università di Pisa, Pisa, Italy