Growth of high-quality ZnO nanowires without a catalyst

Abstract

In this study, an efficient method to achieve a wide range of high-quality zinc oxide (ZnO) nanostructures through zinc powder evaporation at lower temperatures is developed. ZnO nanowires could be synthesized on n-type silicon substrates by a simple thermal-evaporation technique without a catalyst at 550, 600, and 650 °C. Samples are annealed in wet oxygen and ambient argon gases. Surface morphology, crystallinity, and optical properties of the ZnO nanowires are examined by scanning electron microscopy, X-ray diffraction, and photoluminescence measurement. The optimum temperature for synthesizing high-density, long ZnO nanowires was determined as 650 °C. The possible growth mechanism of ZnO nanowires is also proposed.