Fabrication, characterization, and kinetic study of vertical single-crystalline CuO nanowires on Si substrates

Shao-Liang Cheng,Ming-Feng Chen

doi:10.1186/1556-276x-7-119

Abstract

We report here on the first study of the growth kinetics of high-yield, vertical CuO nanowires on silicon substrates produced by the process of thermal oxidation. The length of the CuO nanowires could be tuned from several to tens of micrometers by adjusting the oxidation temperature and time. The grown CuO nanowires were determined to be single-crystalline with different axial crystallographic orientations. After a series of scanning electron microscopy examinations, the average length of CuO nanowires produced at each temperature was found to follow a parabolic relationship with the oxidation time. The parabolic growth rate at different oxidation temperatures was measured. The activation energy for the growth of CuO nanowires calculated from an Arrhenius plot was found to be about 174.2 kJ/mole. In addition, the current-voltage characterization indicated that the sample with high-density CuO nanowires exhibited ohmic behavior, and its resistance was found to significantly decrease with increasing environmental temperature. The result can be attributed to an increase in the number of carriers at higher temperatures.

Highlights

In recent years, one-dimensional [1D] metal-oxide semiconductor nanostructures, such as whiskers and nanowires, have attracted increasing interest due to their unique properties and variety of potential applications [1,2,3]
Cu film-coated Si samples oxidized in air at 400°C to 500°C for different periods of time were systematically examined by cross-sectional SEM to show the evolution of the length of the CuO nanowires with the oxidation temperature and time
Summary and conclusions In summary, the present study demonstrates that by controlling the thermal oxidation temperatures and time, length-tunable, single-crystalline CuO nanowires can be successfully produced on silicon substrates

Summary

Introduction

One-dimensional [1D] metal-oxide semiconductor nanostructures, such as whiskers and nanowires, have attracted increasing interest due to their unique properties and variety of potential applications [1,2,3]. We show the successful fabrication of length-tunable, vertically aligned CuO nanowires on Cu film-coated Si substrates by thermal oxidation in air.

Results

Conclusion