Electron density of states for silicon

The density of states for silicon was calculated using the program Quantum Espresso (version 4.3.1). Notice that the bandgap is too small. This commonly occurs for semiconductors when the bandstructure is calculated with density functinal theory. Another calculation that uses wien2K.

The common way to fix the small bandgap problem is simply to increase the energies of the states in the conduction band until the bandgap is the right size. This is sometimes known as a scissors operation. The density of states is cut in the bandgap and pushed apart until the bandgap is correct. The density of states after this correction has been performed is shown below.

The table below uses the corrected bandgap for the density of states.

Lattice constant: a = 5.43095 Å.