Sammendrag
We present a study of the electronic structure and optical properties of Si3N4 and Si2N3H in crystalline and amorphous phases by first-principles calculations. We find that besides structural disorder those matrix atoms with dangling and floating bonds contribute to energy levels close to the Fermi level. From a comparative analysis of calculated optical spectra we conclude that the difference in optical properties between crystalline and amorphous silicon nitrides—either hydrogenated or unhydrogenated—is only small. It is present mainly in the energy range close to the fundamental band gap. At larger energies the difference is negligible. It is found that the structural disorder in silicon nitrides investigated does not affect essentially the electronic structure and optical properties of these materials. It is concluded that such amorphous silicon nitrides can be used instead of their crystalline counterparts for various applications in which optical properties of such materials are important.
This research was first published in the Journal of Applied Physics. © AIP Publishing