Erich C. Walter

Photoluminescence and polarized photodetection of single ZnO nanowires

Single crystal ZnOnanowires are synthesized and configured as field-effect transistors.Photoluminescence and photoconductivity measurements show defect-related deep electronic states giving rise to green-red emission and absorption. Photocurrent temporal response shows that current decay time is significantly prolonged in vacuum due to a slower oxygen chemisorption process. The photoconductivity of ZnOnanowires is strongly polarization dependent. Collectively, these results demonstrate that ZnOnanowire is a remarkable optoelectronic material for nanoscale device applications.

Electronic devices from electrodeposited metal nanowires

Abstract Based on their electronic conductivity behavior, metallic nanowires may have electronic applications ranging from interconnects to sensors. We have recently developed an electrochemical method for synthesizing metal nanowires (Pd, Cd, Mo, Au, Ag, Cu,…) ranging in diameter from a few tens of nanometer to 1 μm with millimeter lengths. These nanowires are prepared by the electrodeposition of metal at step edges present on a graphite surface. These nanowires can be used to connect metal nanoparticles (Ni, Au…) or, once transferred in a polymer cast, can operate as sensors. In this paper, we shall describe the general method of preparation of such naked and beaded nanowires as well as how may these nanowires be manipulated to make electronic devices. As an example of such nanodevice, a brief overview of the characteristics of the first nanowire-based sensor for hydrogen gas (H 2 ) will be given.