Effects from adsorption of organic species on the surface of nanomaterials have been investigated. Exposure to organic contaminants during material processing, handling and environmental exposure is unavoidable during the manufacturing process of nanoscale materials. In addition, at the nanoscale, surface area to volume ratios increase and surface effects will have an increasing influence on the material properties. Experimentally measured electrical properties of gold nanowires and composition will be presented. The results indicated that C, C—O—C and C=O are adsorbed at the surface of the gold nanowires. These surface contaminants are believed to cause the increase in measured resistivity. A theoretical study was performed to investigate diffusion of these contaminants into the first surface layer, which may act as scattering mechanisms for current flow.
Magnetic properties of Fe nanowire arrays (NWs) electrodeposited in anodic alumina membranes have been studied. The influence of nanowire geometry (length, pore diameter) and an external magnetic field applied during electrodeposition process on the magnetic properties of nanowire arrays was investigated. With the use of the X-ray diffraction analysis the structure of iron wires was determined. The iron wires have the regular Body Centered Cubic structure. Magnetic measurements show that shape anisotropy aligns the preferential magnetization axis along the wire axis. It was found that the application of an external magnetic field in a parallel direction to the sample surface induces magnetic anisotropy with an easy axis of magnetization following the nanowire axis. The dependence of the height of Fe wires on the electrodeposition time was determined.
In this study a two-step short wet etching was implemented for the black silicon formation. The proposed structure consists of two steps. The first step: wet acidic etched pits-like morphology with a quite new solution of lowering the texturization temperature and second step: wires structure obtained by a metal assisted etching (MAE). The temperature of the process was chosen due to surface development control and surface defects limitation during texturing process. This allowed to maintain better minority carrier lifetime compared to etching in ambient temperature. On the top of the acidic texture the wires were formed with optimized height of 350 nm. The effective reflectance of presented black silicon structure in the wavelength range of 300-1100 nm was equal to 3.65%.