Combinatorial Screening of Luminescent and Structural Properties in a Ce3+-Doped Ln-Al-Si-O‑N (Ln = Y, La, Gd, Lu) System: The Discovery of a Novel Gd3Al3+xSi3–xO12+xN2–x:Ce3+ Phosphor

The discovery of novel phosphors for use in light emitting diodes (LED) has gained in significance because LED-based solid-state lighting applications now attract a great deal of attention for energy savings and environmental concerns. Recent research trends have centered on the discovery of novel phosphors, not on slight variations of well-known phosphors. In a real sense, novelty goes beyond simple variations or improvements in existing phosphors. A brilliant strategy for the discovery of novel phosphors is to introduce an appropriate activator to existing inorganic compounds. These compounds have structures that are well-defined in crystallographic structure databases, but they have never been considered as a phosphor host. Another strategy is to discover new host compounds with structures that cannot be found in existing databases. We have simultaneously pursued both strategies by employing metaheuristics-assisted combinatorial material search techniques. In the present investigation, we screened a search space consisting of Ln-Al-Si-O-N (Ln = Y, La, Gd, Lu), and thereby we discovered a blue-light-emitting novel phosphor, Gd3Al3+xSi3–xO12+xN2–x:Ce3+, with a monoclinic system in the C2 space groupa potential candidate for UV-LED applications.