Optical transitions in hydrogenated amorphous silicon

We study how the various kinds of optical transitions which occur within hydrogenated amorphous silicon contribute to the spectral dependence of the complex component of the dielectric function. While the optical transitions from the valence band band states to the conduction band band states are found to play a dominant role in determining the magnitude of this function for photon energies in excess of the optical gap, other types of optical transitions are also found to be important. We suggest that these other types of optical transitions should not be neglected when interpreting the optical properties of hydrogenated amorphous silicon. (C) 2002 American Institute of Physics.