Investigation of the electronic structure and photoluminescence properties of Eu 3+ in Sr 2Mg 1-xZn xSi 2O 7 (0≤ x ≤ 1)

Abstract

Undoped and Eu 3+-doped Sr 2Mg 1-xZn xSi 2O 7 (0 ≤ x ≤ 1) powder crystals were obtained by conventional solid-state reaction. X-ray diffraction, inductively coupled plasma analysis, and Fourier transform infrared spectroscopy results implied that a complete solid-solution formed between Sr 2MgSi 2O 7 and Sr 2ZnSi 2O 7 as well as local structural adjustment. Excitation spectra exhibited O 2--Eu 3+ charge transfer (CT) bands centered at 250 nm for Sr 2MgSi 2O 7:Eu 3+ and 258 nm for Sr 2ZnSi 2O 7:Eu 3+. Emission spectra exhibited a major band around 616 nm, which showed the environment around Eu3+ was non-centrosymmetric in both Sr 2MgSi 2O 7:Eu 3+ and Sr 2ZnSi 2O 7:Eu 3+. In addition, first principles calculations within the local density approximation (LDA) of density functional theory (DFT) were used to calculate the electronic structure of Sr 2MgSi 2O 7 and Sr 2ZnSi 2O 7. Calculated results were correlated with experimental UV-vis reflection spectra and the observed shift of the O 2--Eu 3+ CT band. © 2012 Science China Press and Springer-Verlag Berlin Heidelberg.