The exploration of structure evolution and photoluminescence property in Ca9Al1-xYx(PO4)7:Eu2+ solid solution phosphors via the construction of bi-directional relationships

Exploring the process of structure evolution and mechanism of controllable luminescence in the solid solution phosphors is meaningful but still challenging. Herein, new solid solution phosphors of Ca9Al1-xYx(PO4)(7):Eu2+ were selected as examples to address the challenging via the construction of bidirectional relationships between structure evolution and photoluminescence property. In Ca9Al1-xYx(PO4)(7), the structure evolution caused the redistribution of Eu2+ in the multiple cationic sites, accompanied by the changes of emission color from blue (0.1828, 0.1192) to cyan (0.1723, 0.3305), which were investigated by Gaussian fitting, decay time, and bond energy theory. Conversely, the Gaussian fitting peaks displayed different blue or red shifts in the process of structure evolution, which could reversely reflect the specific changes of bond lengths in each cationic site and were helpful for exhaustive understanding the process of structure evolution in Ca9Al1-xYx(PO4)(7).Besides, the thermal stability behaviors of Ca8.95Al1-xYx(PO4)(7):0.05Eu(2+) exhibited that the decline rate of low energy bands were faster than that of high energy bands due to the thermally active phonon-assisted effect. The constructed bidirectional relationships pave a feasible way to investigate the variations of structure evolution and emission properties, which will be helpful for the design of new kinds of phosphors. (C) 2019 Elsevier B.V. All rights reserved.