Ab initio calculation of the electronic structure and spectroscopic properties of spinel γ-Sn3N4 -: art. no. 045202

The electronic structure and physical properties of gamma-Sn3N4 in the spinel structure are investigated by first-principles calculations. The calculated band structure, electronic bonding, and optical properties are compared with two well-studied spinel nitrides gamma-Si3N4 and gamma-Ge3N4. gamma-Sn3N4 is a semiconductor with a direct band gap of 1.40 eV and an attractive small electron effective mass of 0.17. Its optical properties are different from that of gamma-Si3N4 and gamma-Ge3N4 because of the difference in the conduction band minimum. The Sn K, Sn L-3, Sn M-5, and N K edges of the x-ray-absorption near-edge structure spectra in gamma-Sn3N4 are calculated using a supercell approach and are found to be rich in structures. These spectra are discussed in the context of the electronic structure of the unoccupied conduction band in the presence of the electron core-hole interaction. These calculated spectra can be used for the characterization of this novel compound.