Fabrication of ZnO tetrapods on silicon substrate by thermal evaporation

Large-scale ZnO tetrapods have been fabricated on silicon substrate by a simple thermal evaporation method at 700 °C without vapor transportation and characterized by FESEM, XRD, Micro-Raman, and PL, respectively. FESEM images indicate that the length of tetrapod arm is about 3–4 μm, and the diameter of the tip is about 50 nm. XRD and Raman spectrum reveal that ZnO tetrapods are highly pure hexagonal wurtzite structure. The PL spectrum indicates that the ZnO tetrapods have strong green emission at 510 nm.