Near-Infrared Quantum Cutting Long Persistent Luminescence

By combining the unique features of the quantum cutting luminescence and long persistent luminescence, we design a new concept called near-infrared quantum cutting long persistent luminescence (NQPL), which makes it possible for us to obtain highly efficient (>100%) near-infrared long persistent luminescence in theory. Guided by the NQPL concept, we fabricate the first NQPL phosphor Ca2Ga2GeO7: Pr3+, Yb3+. It reveals that both the two-step energy transfer of model (I) and the one-step energy transfer of model (IV) occur in P-3(0) levels of Pr3+. Although the actual efficiency is not sufficient for the practical application at this primitive stage, this discovery and the associated materials are still expected to have important implications for several fields such as crystalline Si solar cells and bio-medical imaging.