Structural, Raman, and photoluminescence properties of double-shelled coaxial nanocables of In2O3 core with ZnO and AZO shells

Abstract

We synthesized In2O3/ZnO/Al-doped ZnO (AZO) core-double shell nanowires, in which the inner shell (ZnO) and the outer shell (AZO) have been subsequently deposited on the core In2O3 nanowires. With their one-dimensional morphology being preserved, the X-ray diffraction (XRD), lattice-resolved transmission electron microscopy (TEM) image, selected area electron diffraction, and Raman spectrum coincidentally revealed that the shell was comprised of hexagonal ZnO phase. In addition, TEM-EDX investigation revealed the presence of Al elements in the shell region. The thermal annealing at 700 degrees C did not significantly change the nanowire morphology, however, the XRD spectrum indicated that the ZnO phase was crystallized by the annealing. PL spectrum of the 700 degrees C-annealed In2O3/ZnO/AZO core-double shell nanowires was comprised of three Gaussian bands at approximately 2.1 eV, 2.4 eV, and 3.0 eV, respectively. The integrated intensities of 2.1 eV-, 2.4 eV-, and 3.0 eV-bands were decreased by the thermal annealing. This study will pave the road to the preparation and applicaition of double-shelled nanowires.