摘要
We demonstrate a method to synthesize GaN-ZnGa 2 O 4 core-shell nanowire and ZnGa 2 O 4 nanotube arrays by a low-temperature hydrothermal process using GaN nanowires as templates. Transmission electron microscopy and X-ray photoelectron spectroscopy results show that a ZnGa 2 O 4 shell forms on the surface of GaN nanowires and that the shell thickness is controlled by the time of the hydrothermal process and thus the concentration of Zn ions in the solution. Furthermore, ZnGa 2 O 4 nanotube arrays were obtained by depleting the GaN core from GaN-ZnGa 2 O 4 core-shell nanowire arrays during the reaction and subsequent etching with HCl. The GaN-ZnGa 2 O 4 core-shell nanowires exhibit photoluminescence peaks centered at 2.60 and 2.90 eV attributed to the ZnGa 2 O 4 shell, as well as peaks centered at 3.35 and 3.50 eV corresponding to the GaN core. We also demonstrate the synthesis of GaN-ZnGa 2 O 4 heterojunction nanowires by a selective formation process as a simple route toward development of heterojunction nanodevices for optoelectronic applications. © 2013 American Chemical Society.