Red, Green, and Blue Luminescence from ZnGa₂O₄ Nanowire Arrays

Large-area (>1 cm 2 ), vertically aligned ZnGa 2 O 4, Mn 2+ -doped ZnGa 2 O 4 (ZnGa 2 O 4:Mn 2+ ) and Cr 3+ -doped ZnGa 2 O 4 (ZnGa 2 O 4:Cr 3+ ) nanowire arrays were synthesized by a two-step thermal evaporation method using ZnO nanowire arrays as the templates followed by reaction with Ga and/or dopant (Mn or Cr) vapors. Bright red, green, and blue luminescence was achieved, respectively, from ZnGa 2 O 4:Cr 3+, ZnGa 2 O 4:Mn 2+, and ZnGa 2 O 4 nanowire arrays under ultraviolet light irradiation. The realization of three primary colors from one host material suggests that full color display based on ZnGa 2 O 4 nanowires might be achievable.