Study of the structural and luminescent properties of ZnO nanorod arrays with hydrogen peroxide treatment

Abstract

One-dimensional nanostructures, such as nanowires, nanoneedles, nanobelts and nanotubes, have been extensively studied in recent years. These fascinating structures have the excellent physical properties owing to their geometry with high aspect ratio and modify the light-matter interaction. However, the defects of these structures are the obstacles for the practical applications. We report the influence of the hydrogen peroxide (H 2 O 2 ) treatment on the point defects and structural defects of ZnO nanorods grown on n-type silicon. The ZnO nanorod arrays are prepared by low-cost hydrothermal method and the H 2 O 2 treatments are investigated in two different approaches. One is to immerse ZnO nanorod samples into H 2 O 2 solution. The other is a pre-treatment of spin-coating H 2 O 2 solution on the seed layer before the growth of the ZnO nanorods. In the first approach, we found that the ultraviolet (UV) emission peak of the ZnO nanorods photoluminescence (PL) spectra was strongly dependent on the immersion time. In the second approach, the H 2 O 2 solution not only influences the quality of the seed layer, but also the amount of the oxygen interstitial defects in the ZnO nanorods grown thereon. As a result, the UV emission intensity from the ZnO nanorods is enhanced almost five times. These effects are attributed to oxygen desorption through oxidation-reduction reactions of hydrogen peroxide on the ZnO surface. The ZnO nanorod arrays with few oxygen interstitial defects are prepared by low-cost and low-temperature hydrogen peroxide treatments, which are compatible with glass and polymer substrates and expected to enable the fabrication of optoelectronic device with excellent performance.