Uniform lanthanide-doped Y2O3 hollow microspheres: Controlled synthesis and luminescence properties

► Uniform and size-controlled lanthanide-doped pure cubic phase Y2O3 hollow microspheres. ► Bright up-conversion red, green, blue emission with high purity. ► Intense high-purity red down-conversion light emission. ► The energy transfer from Tb3+ to Eu3+ ions.