New ternary europium aluminate luminescent nanoribbons for advanced photonics

Developing novel one-dimensional (1D) luminescent nanostructures (e.g., nanowires and nanoribbons) is highly desired for enabling progress in nanophotonics and other emerging optical technologies. Previous studies on 1D luminescent nanostructures were mostly focused on elemental and binary semiconductor materials, the light emission of which originates from the radiative recombination of electrons and holes via either intrinsic states or extrinsic defect states. Herein, three kinds of ternary europium aluminate nanoribbons are reported that have localized Eu²⁺ luminescent centers and exhibit new compositions, new crystal lattice structures, and new luminescence properties and mechanisms. These three europium aluminate nanoribbons are: blue luminescent EuAl₆O₁₀ with a new composition and a new tetragonal lattice structure, green luminescent EuAl ₂O₄ with a monoclinic lattice structure, and orange luminescent EuAl₂O₄ with a new hexagonal lattice structure and extremely large band width and Stokes shift of emission. These materials have promising applications as nanometer-scale light generators and waveguides in nanophotonics and as light converting phosphors in warm white light-emitting diodes. Three kinds of europium aluminate nanoribbons associated with luminescence colors of blue, green, and orange are fabricated by a strictly controlled thermal evaporation technique. These europium aluminates exhibit new compositions, new crystal lattice structures, and new luminescence properties and mechanisms. They have very promising applications in emerging optical technologies.