Home > Seminars > subSeminar
Building and converting nanowires
| Speaker: | Prof. Uros Cvelbar |
| Time: | Wed, 2014-11-18 10:30 - 11:30 |
| Address: | physics building 709 |
Abstract
There has been tremendous interest and progress with plasma synthesis of inorganic nanowires (NWs) for improved applications in recent years. Nevertheless, much of the progress only resulted in NWs with diameters much greater than their respective quantum confinement scales, i.e. 10–100 nm. Even at this scale, NW-based materials offer enhanced charge transport and smaller diffusion length scales for improved performance with various electrochemical and photo-electrochemical energy conversion and storage applications. However, many times synthesized materials don’t meet specific properties for optimal performance in certain devices, e.g. band gap energies, or they are even hard to obtain. These deficiencies can be eliminated by additional plasma conversion processes, where we can substitute atoms in crystal networks or controllably release them and create defects. Here the NWs or one-dimensional crystalline materials of metal oxides with diameters less than 100 nm provide a useful platform for creating new materials either as substrates for heteroepitaxy or through the phase transformation with reaction. Specific results with single crystal phase transformation of e.g. hematite (a-Fe2O3) to pyrite (FeS2) NWs will be presented to illustrate the viability of using NWs for creating new materials through plasma particle reformation. Furthermore, the metal oxide NWs can be altered and modified also by other energetic particles like electrons and UV photons, which cause irradiation damages and release atoms from crystal networks. All these processes lead to improved properties, tailored band gaps and increased performance of NWs in devices.
