Atomic and Electronic Structure Investigation and Luminescence Property of Eu2+-Doped β-SiAlON Green Phosphor: Ab initio Calculations

The atomic and electronic structure of Eu-doped β-SiAlON with various Al–O pair concentrations was calculated using density functional theory. The luminescence properties were analyzed by using quantitative calculation of the bandgap and the wavelength. Interstitially doped Eu ion was found near N atoms in the atomic channel parallel to the [0001] axis and the lattice parameters of the primitive cell became larger as the Al–O pair concentration increased. The additional states originated from the hybridization of Eu 4f with Si 3p and N 2p. The calculated wavelengths from the energy gap between the valance band maximum and the extra level was about 540 nm in the high Al–O pair concentration. The calculated results are well agreed with experimental results.