Insight into a concentration-sensitive red-emitting phosphor Li2Ca4Si4O13:Eu3+ for multifunctional applications: Crystal structure, electronic structure and luminescent properties

Abstract

Lithium-containing silicate compounds have attracted so much attention in recent years for applications in energy storage and illumination source due to their rigid structure and good electrical conductivity. In this study, a Eu3+ doped lithium-containing silicate red phosphor, Li2Ca4Si4O13:Eu3+, was explored by using structural computational simulations and systematic experiments for multifunctional applications. As a result, due to the quite non-central symmetry of the Ca2+ sites (C1 symmetry), the strong 4f-4f excitations in near ultraviolet region were observed. Under near ultraviolet and cathode ray light excitation, Li2Ca4Si4O13:Eu3+ phosphor has an efficient red emission with good thermal stability and ageing resistance. Furthermore, Li2Ca4Si4O13:Eu3+ phosphor exhibits a concentration-sensitive behavior induced by the change of site symmetry. The results show that it is feasible to develop near-ultraviolet and cathode ray light excited red phosphors in lithium-containing silicate compounds.