Site spectroscopy probing of Eu3+ incorporated into novel LiYxSryZrO3+α host matrix

In this work, we investigated the spectroscopic properties of LiYxSryZrO3+α: Eu3+, a red emitting nanophosphor based on SrZrO3 perovskite. The synthesis process was an auto-combustion process. X-ray diffractograms show the orthorhombic structure of SrZrO3. Photoluminescence (PL) excitation spectra display a split charge transfer band revealing the presence of two possible sites for the Eu3+ ions. The emission spectra at 231 nm excitation illustrate the dominance of the 5D0 - 7F1 transition, which is an indication that the smaller sized Eu3+ ions are mostly situated at the more ordered (symmetric) Sr2+ sites. The emission spectra at 292 nm & 397 nm excitations show the dominance of 5D0 - 7F2 transition which suggests some of the Eu3+ ions are also situated at the distorted Zr4+ sites. Both the intensity parameters, asymmetry ratio and the decay lifetimes of the nanophosphors show dependence on Y3+ concentration, signifying a modification in the host structure. Maximum quantum efficiency value of ≈ 46% was obtained for the nanophosphors which indicate the need for improvement for practical applications. CIE coordinates show the suitability of this phosphor for both red emission in LED and as a complementary colour for white LED applications.