Bandstructure Lab uses the sp3s*d5 tight binding method to compute E(k) for bulk, planar, and nanowire semiconductors. Using this tool, you can quickly compute and visualize the bandstructures of bulk semiconductors, thin films, and nanowires for various materials, growth orientations, and strain conditions. Physical parameters such as the bandgap and effective mass can also be obtained from the computed E(k). The bandedges and effective masses of the bulk materials and the nanostructures structures can be analyzed as a function of various strain conditions.

As explained in a related seminar, correct band structure is essential for modeling devices at the nano scale.

Chapter 5 of Quantum Transport by S. Datta (Cambridge, 2005)

Starting from version 2.0, the tool is now powered by a C code named OMEN. All previous versions were coded in Matlab.

Version 2.0 is a radical new release of the code and we are aware of several issues that are not fully stable. We very much appreciate feedback if certain features of the tool do not function properly. The last 1.X version of Bandstructure Lab is still available at the following link: Bandstructure Lab Version 1.2 (published).

Phyiscal Limitations:

Different Tight-binding models can give different electron and hole effective masses. This happens since different band models give different curvatures.Always a higher and more sophisticated band model will give better estimation of effective masses. Eg: sp3d5s* TB models give better estimate of effective mass compared to sp3s* TB models.

Known issues with Version 2.0:

bulk effective mass table is not correct for light, and heavy hole bands charge self-consistent calculation appears to be unstable for some devices nanowire dimensions exceeding 5-6nm in diameter appear to crash the simulations. More work is needed in the tool

Tool Versions

1. nanoelectronics