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

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 Eu 3+ doped lithium-containing silicate red phosphor , Li 2 Ca 4 Si 4 O 13 :Eu 3+ , 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 Ca 2+ sites (C 1 symmetry), the strong 4f-4f excitations in near ultraviolet region were observed. Under near ultraviolet and cathode ray light excitation , Li 2 Ca 4 Si 4 O 13 :Eu 3+ phosphor has an efficient red emission with good thermal stability and ageing resistance. Furthermore, Li 2 Ca 4 Si 4 O 13 :Eu 3+ 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.