Morphology Control and Photoluminescent Properties of Bundled ZnO Nanorods Array Based on Silicon Nanoporous Pillar Array

A silicon nanoporous pillar array (Si-NPA) is a silicon hierarchical structure with regularly patterned surface morphology. An array of bundled ZnO nanorods was grown based on Si-NPA by a catalyst-free thermal evaporation method. The morphology of ZnO/Si-NPA was found to be greatly affected by the growth parameters such as the grown temperature and the ratio nitrogen and oxygen. The room-temperature photoluminescence (PL) spectrum of ZnO/Si-NPA showed a violet emission at ∼410 nm and a blue-green emission around 500 nm, which were attributed to the PL of Si-NPA substrate and oxygen vacancies of ZnO, respectively. The results indicated that ZnO/Si-NPA is a promising optical material.