Spectroscopic properties and energy level location of Eu2+ in Sr2Si5N8 phosphor
Journal
Optical Materials
Journal Volume
37
Pages
734-739
Date Issued
2014
Author(s)
Abstract
In this contribution luminescence properties of Sr2-xSi5N8:Eux2+ (x = 0.02 and 0.1) at temperatures from 10 to 600 K are presented. Both materials exhibit broad band red emission assigned to the parity allowed 4f65d1 → 4f7 transitions in Eu2+ ions occupying two different crystallographic sites labeled as Eu(Sr1) and Eu(Sr2). For low concentration of dopants only Sr1 site is occupied, whereas for higher concentration both Sr1 and Sr2 sites are occupied. Optical data are used to construct configurational coordination diagrams of the Eu(Sr1) and Eu(Sr2) centers in Sr2Si5N8 lattice. Effects of temperature luminescence quenching and luminescence lifetime shortening were related to ionization of Eu2+ ions and anharmonicity of adiabatic lattice potential. Effect of non-homogeneity of the Eu2+ occupation between the Sr1 and Sr2 sites is discussed by considering the energies of the ground states of Eu(Sr1) and Eu(Sr2) in respect to the valance and conduction bands.
In this contribution luminescence properties of Sr2-xSi5N8:Eux2+ (x = 0.02 and 0.1) at temperatures from 10 to 600 K are presented. Both materials exhibit broad band red emission assigned to the parity allowed 4f65d1 → 4f7 transitions in Eu2+ ions occupying two different crystallographic sites labeled as Eu(Sr1) and Eu(Sr2). For low concentration of dopants only Sr1 site is occupied, whereas for higher concentration both Sr1 and Sr2 sites are occupied. Optical data are used to construct configurational coordination diagrams of the Eu(Sr1) and Eu(Sr2) centers in Sr2Si5N8 lattice. Effects of temperature luminescence quenching and luminescence lifetime shortening were related to ionization of Eu2+ ions and anharmonicity of adiabatic lattice potential. Effect of non-homogeneity of the Eu2+ occupation between the Sr1 and Sr2 sites is discussed by considering the energies of the ground states of Eu(Sr1) and Eu(Sr2) in respect to the valance and conduction bands.
SDGs
Type
journal article