Cathodoluminescence characterization of ZnO nanorods synthesized by chemical solution and of its conversion to ellipsoid
- PDF / 495,483 Bytes
- 7 Pages / 584.957 x 782.986 pts Page_size
- 50 Downloads / 192 Views
Sadaf Jamil-Rana,b) Omer Nur, and Magnus Willander Department of Science and Technology, Linköping University, Norrköping SE-60174, Sweden
Jun Lu and Lars Hultman Department of Physics, Chemistry and Biology, Linköping University, Linköping SE-58183, Sweden (Received 11 May 2014; accepted 14 August 2014)
A facile and reproducible low-temperature (80 °C) solution route has been introduced to synthesize ZnO ellipsoids on silicon substrate without any pretreatment of the substrate or organic/inorganic additives. Scanning electron microscopy, transmission electron microscopy, and x-ray diffraction spectroscopy are performed to analyze the structural evolution, the single crystalline nature, and growth orientation at different stages of the synthetic process. The sequential formation mechanisms of heterogeneous nucleation in primary and secondary crystal growth behaviors have been discussed in detail. The presented results reveal that the morphology of micro/nanostructures with desired features can be optimized. The optical properties of grown structures at different stages were investigated using cathodoluminescence (CL). The monochromatic CL images were recorded to examine the UV and visible band emission contributions from the different positions of the intermediate and final structures of the individual ZnO ellipsoid. Significant enhancement in the defect level emission intensity at the central position of the structure reveals that the quality of the material improves as the reaction time is extended. I. INTRODUCTION
Advances in the fabrication of nanostructures of different materials with desired tunable morphologies have been fueled up due to the demonstration of their prominent aspects in optoelectronics, catalysis, sensing, and medicine,1–9 as compared to the bulk material, not only in basic scientific research but also in technological applications. Among various oxides, ZnO is a fascinating material containing the most plenteous family of the nanostructures with a wide band gap and large exciton binding energy. Additionally, the reason for focusing more attention on research toward the ZnO material is due to its promising versatile semiconducting and excellent piezoelectric properties, and ease of use in fabrication.10–12 One-dimensional ZnO nanostructures e.g., nanorods, nanobelts, nanohelix, nanobridges, nanonails, mesoporous polyhedral cages, and nanotubes,13–18 etc. have proven their potential in diverse fields. In many applications, the growth of the crystalline structure, a large surfaceto-volume ratio, shape, size, and density of the nanostructures are the key factors.19–23 These factors play a Address all correspondence to these authors. a) e-mail: [email protected] b) e-mail: [email protected] DOI: 10.1557/jmr.2014.242 J. Mater. Res., Vol. 29, No. 20, Oct 28, 2014
http://journals.cambridge.org
Downloaded: 12 Mar 2015
crucial role in the agglomeration in the growth process to achieve diverse shaped morphologies. The extension of the surface area can be achieved by decreasing the particle size and d
Data Loading...
