ZnGa2O4 nanotubes with sharp cathodoluminescence peak

Single-crystal ZnGa2O4 nanotubes were grown using well-aligned ZnO nanorods as templates by a vapor transport method. Ga and O vapors were reacted with ZnO to form ZnO/ZnGa2O4 core-shell nanostructure, and single-crystal ZnGa2O4 nanotubes were obtained by the removal of ZnO cores with a dilute HCl solution. The cathodoluminescence spectra indicate that the ZnGa2O4 nanotubes emit near ultraviolet (UV) and blue lights (380 and 464 nm). The sharp near UV peak shall be beneficial for optical applications.