Identification and quantification of varied valence Eu ions by photoluminescence spectrum and electron energy loss spectrum

For many instances in phosphor materials, mixed valence Eu co-existing phenomenon has been widely reported. It is then of great importance and necessity to identify the charge state and to quantify the content of varied valence Eu ions, because the luminescent properties of phosphors are closely dependent on the valence state of Eu ions and its content. Photoluminescence (PL) spectrum on the emission profile and electron energy loss spectrum (EELS) about the M-edges carry useful information on the valence state of Eu ions. In this work, PL and EELS were employed to identify the charge state of Eu ions in LaAlO3 phosphor, basing on the different emission profile of PL and M5/M4 ratio of EELS signals for varied valence Eu ions. And the relative content ratio of Eu2+/Eu3+ for these incorporated Eu ions in LaAlO3 host was quantified by the PL and EELS.