The synthesis of ZnO nanowires and their subsequent use in high-current field-effect transistors formed by dielectrophoresis alignment

The synthesis of zinc oxide (ZnO) nanowires was achieved by thermal evaporation on a steel alloy substrate. Various material characteristics such as X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and Raman scattering analysis indicated that the synthesized ZnO nanowires were single crystalline with a wurtzite hexagonal phase, and were preferentially synthesized in the c-axis direction. In addition, the straightforward and successful alternating current (AC) dielectrophoresis (DEP) method that can be used to align and manipulate ZnO nanowires as well as to fabricate high-performance multiple-channel field-effect transistors (FETs) with a back-gate structure were also investigated. The DEP results indicated that the number of aligned ZnO nanowires increased with the increasing AC voltages. Moreover, we demonstrated that the DEP-prepared multiple ZnO nanowires FETs can manage on-current exceeding ∼1 μA at a low-bias voltage. Our approach to build up the high-current nano-FETs offers substantial opportunities for further practical electronics and photonics device applications.