Jump to main content
Jump to site search

Issue 40, 2019
Previous Article Next Article

Green persistent luminescence and the electronic structure of β-Sialon:Eu2+

Author affiliations


Divalent europium doped aluminum silicate oxy-nitride (β-Sialon:Eu2+) has been widely used in backlights for liquid-crystal displays due to its outstanding green emission properties. Herein, the persistent luminescence (PersL) performance and electronic structure of β-Sialon:Eu2+ with the general formula Eu0.015Si5.5Al0.485O0.515N7.485 are first reported. The PersL duration is observed to be 400 s after 254 nm irradiation. By virtue of density functional theory (DFT) calculations, we verify that the trap levels responsible for PersL are impurity levels induced by Si–O bonds located below the bottom of the conduction band (CB) on random substitution of Al–O for Si–N in β-Si3N4. The trap depth and density are estimated through experimental data. The charging process for PersL is clarified by the thermoluminescence excitation (TLE) spectrum. The electronic structure diagrams (host referred binding energy, HRBE and vacuum referred binding energy scheme, VRBE) of β-Sialon:Eu2+ are constructed to deeply understand the PersL mechanism and luminescence behavior. We propose a novel strategy to construct the HRBE schemes, i.e. using the onset energy of the thermoluminescence excitation (TLE) spectrum as the energy difference between the 4f ground state and the bottom of the CB to pinpoint the 4f energy level location of Eu2+. This work would allow more rational design of luminescent materials.

Graphical abstract: Green persistent luminescence and the electronic structure of β-Sialon:Eu2+

Back to tab navigation

Supplementary files

Publication details

The article was received on 15 Jul 2019, accepted on 15 Sep 2019 and first published on 17 Sep 2019

Article type: Paper
DOI: 10.1039/C9TC03833G
J. Mater. Chem. C, 2019,7, 12544-12551

  •   Request permissions

    Green persistent luminescence and the electronic structure of β-Sialon:Eu2+

    S. Wang, X. Liu, B. Qu, Z. Song, Z. Wang, S. Zhang, F. Wang, W. Geng and Q. Liu, J. Mater. Chem. C, 2019, 7, 12544
    DOI: 10.1039/C9TC03833G

Search articles by author