Authors: C-H. Wang, J. Yang, K. Shum, T. Salagaj, Z.F. Ren, Y. Tu
Affilation: First Nano, United States
Pages: 126 - 129
Keywords: ZnO, nanowire, large area
It has been found that Zinc oxide (ZnO) nanowires have great potential in many applications. Currently, the most commonly used method to grow ZnO nanowires is to use the vapor transport method. The morphology of the ZnO nanowire is determined by the substrate temperature and gas flow. Previously a uniform ZnO nanowire array could only be obtained on a small area less than 0.5 inch by 0.5 inch due to the temperature gradient between the source and substrate temperatures. This paper reports a novel growth system design that uses a dedicated heater for the ZnO solid source, a defined transition zone to isolate the source and substrate temperatures and a three zone furnace to achieve a uniform temperature over a large area (2 inches by 2 inches). The ZnO source material and substrate can be well controlled in a wide range of temperatures in order to obtain the optimum growth conditions. The reacting gas (O2) can be introduced into system at different locations to improve growth efficiency. We have demonstrated the growth of uniform ZnO nanowire arrays on Si and sapphire substrates and ZnO nanowires on graphite flakes over a large area. Photoluminescence measurement over 49 points on the 2” sapphire substrate also proves the uniformity of ZnO nanowire. This method can also be applied to GaN, In2O3 and many other nanowire materials as well. It provides an inexpensive and robust process for making nanowire based devices with large areas.