The mechanical properties of vertical single-crystal ZnO nanowires on ZnO:Ga/glass templates were characterized by nanoindentation experiments in this work. The results from x-ray diffraction and Raman spectra show good crystal quality for the ZnO nanowires. The buckling loads were found to be 1465 and 215 μN for ZnO nanowires of 100 and 30 nm diameters, respectively. When the fixed-fixed column mode was used, it was found that the Young's modulus values of the ZnO nanowires of 100 and 30 nm diameters were 117 and 232 GPa, while the critical buckling strains were 0.62% and 0.35%, respectively. On the other hand, when we employed the fixed-pinned column mode, it can be seen that the Young's modulus values were 229 and 454 GPa, while the critical buckling strains were 0.32% and 0.18%, respectively. Buckling behaviour of the ZnO nanowires was significantly predicted by the Euler buckling model in this work.

No abstract

No abstract

The adhesion of microorganisms on a patterned polyurethane surface was studied simultaneously online and in situ with a quartz crystal microbalance (QCM) and an atomic force microscope (AFM). The specific interaction between Saccharomyces cerevisiae cells and their fingerprints formed by molecular imprinting results in a typical Sauerbrey behaviour, when adhesion events are observable with an AFM. The sensor response due to adsorption of Gram positive Leuconostoc oenus, however, shows non-Sauerbrey behaviour. Bacteria, naturally being smaller than yeast cells, were 'invisible' to liquid phase AFM-measurements, which is due to a weaker surface interaction. Thus, AFM measurements give a hint for unusual frequency enhancements in QCM microorganism measurements.

We demonstrate that heterojunction photovoltaics based on hydrothermal-grown In2S3 on p-Si were fabricated and characterized in the paper. An n-type In2S3 nanoflake-based film with unique 'cross-linked network’ structure was grown on the prepared p-type silicon substrate. It was found that the bandgap energy of such In2S3 film is 2.5 eV by optical absorption spectra. This unique nanostructure significantly enhances the surface area of the In2S3 films, leading to obtain lower reflectance spectra as the thickness of In2S3 film was increased. Additionally, such a nanostructure resulted in a closer spacing between the cross-linked In2S3 nanostructures and formed more direct conduction paths for electron transportation. Thus, the short-circuit current density (Jsc) was effectively improved by using a suitable thickness of In2S3. The power conversion efficiency (PCE, η) of the AZO/In2S3/textured p-Si heterojunction solar cell with 100-nm-thick In2S3 film was 2.39%.