Synthesis and Characterization of ZnO/Ag-Doped ZnO Core-Shell Nanowires

In this work, the ZnO/Ag-doped ZnO core shell nanowires were obtained through a facile threestep method, including the hydrothermal process for ZnO nanowires growth, DC sputtering for silver particles deposition on ZnO nanowires and atom layer deposition for ZnO shell layer deposition. The p-type ZnO shell layer was achieved by annealing treatment under oxygen-rich condition. Compared with ZnO and ZnO/Ag/ZnO samples, (002) diffraction peak position of ZnO/Ag-doped ZnO core shell nanowires shifted to small angle side, which indicated that Ag diffused into ZnO lattice as shell layer. Meanwhile, low-temperature photoluminescence (PL) was used to investigate the p-type emission behavior, which can be observed by exciton bound to a neutral acceptor (A X) at 3.354 eV and the recombination of free electron to the acceptor transition (FA) at 3.315 eV in such the Ag-doped ZnO shell layer. In addition, the calculated acceptor binding energy was 124 meV.