ABSTRACT
The use of Si in photonic applications is limited by the indirect
gap of the Si band structure: radiative interband transitions from
the conduction-band minimum (-point) to the top of the valence
band (-point) require electron-phonon coupling in order to satisfy
the momentum conservation rule. Such coupling is quite weak, and
consequently the phonon-assisted emission of a photon results a
very unfavorable process with respect to the direct no-phonon -
radiative transitions.
