Fabrication of PZT/ZnO Core-Shell Nanowires by Metalorganic Chemical Vapor Deposition

We report on fabrication of Pb(Zr,Ti)O₃ (PZT)/ZnO core-shell nanowires (NWs) on Pt/Ti/SiO₂ membrane structure by metalorganic chemical vapor deposition (MOCVD). On the membrane structure, the diameter of ZnO NWs was smaller than those on Pt/Ti/SiO₂/Si substrate. The growth temperature dependence of the diameter of ZnO NWs suggests that the difference in the diameter of ZnO NWs on the membrane and Pt/Ti/SiO₂/Si substrate was caused by a lowering of the growth temperature on the membrane owing to insufficient heating. PZT was uniformly grown onto ZnO NWs on the membrane, and no distinct difference was observed in crystalline properties of PZT. These experimental results indicate that the crystalline properties of PZT/ZnO core-shell NWs on the membrane is as good as those on the surrounding area, and also open the door to novel NW-based piezoelectric vibration energy harvesters in combination with a mechanical resonance of "soft" substrate.