Quantum confinement of edge states in Si crystallites

A theoretical investigation exploring the major physics on the quantum confinement of Si crystallites related to the many band structure, multiple conduction band minima and degenerate valence band maximum of bulk silicon is presented, it shows the overlaps in the k space between the highest occupied states and the lowest unoccupied states in Si crystallites become more significant when the diameter is ⩽15 Å. The highest occupied ${\mathrm{T}}_1$ states, rather than the highest occupied ${\mathrm{T}}_2$ states, could play a more important role for optical transitions in nano Si crystallites.