Photoluminescence in mineral-derived titanosilicates with various Ti-polyhedral types for rare-earth free phosphor

Usually, phosphor is composed by host crystal and doped rare-earth ion which is an efficient luminescent centre. However, rare-earth elements have considerably small Clarke number and are produced from specific area. Since titanate and silicate minerals are relatively deposited in the earth's crust, we focused on titanosilicate mineral with excellent phololuminescent activity, e.g., benitoite and fresnoite. In this article, our recent results about synthesis of mineral-related Ti-including silicates and their PL property are introduced as a brief review. The origin and mechanism of the phololuminescent properties are also described.