The effect of stacking fault formation on optical properties in vertically aligned ZnO nanowires

Vertically aligned ZnO nanowire arrays were grown on Al2O3 (006) and Zn/Al2O3 (006) substrates under the same fabrication condition using metal-organic chemical vapour deposition. The single-crystalline ZnO nanowires grown on Al2O3 and Zn/Al2O3 exhibited different morphology and crystalline characteristics. ZnO nanowires having in-plane or 30 deg.-twist orientations to the Al2O3 were grown on the Zn/Al2O3 while the nanowires fabricated on the Al2O3 exhibited the 30 deg.-twist orientation. In addition, I1 intrinsic stacking faults were observed only in the nanowires grown on the Zn/Al2O3. The insertion of Zn layers changed the growth direction of the ZnO nanowires that induced the difference in their morphology and crystalline structures. Deterioration of the optical characteristics in the ZnO nanowires due to the crystalline defects, i.e. the stacking faults, was also observed