Simplified Nanowire Growth
The engineers devised a way to grow nanowires directly on the electrode. This advance allowed them to create the electron superhighways that deliver electrons from the polymer-nanowire interface directly to an electrode.
If nanowires are going to be used massively in photovoltaic devices, then the growth mechanism of nanowires on arbitrary metallic surfaces is an issue of great importance, said co-author Paul Yu, a professor of electrical engineering at UC San Diegos Jacobs School of Engineering. We contributed one approach to growing nanowires directly on metal.
The UCSD electrical engineers grew their InP nanowires on the metal electrode indium tin oxide (ITO) and then covered the nanowire-electrode platform in the organic polymer, P3HT, also known as poly(3-hexylthiophene). The researchers say they were the first group to publish work demonstrating growth of nanowires directly on metal electrodes without using specially prepared substrates such as gold nanodrops.
Just a layer of metal can work. In this paper we used ITO, but you can use other metals, including aluminum, said Paul Yu.
Growing nanowires directly on untreated electrodes is an important step toward the goal of growing nanowires on cheap metal substrates that could serve as foundations for next-generation photovoltaics that conform to the curved surfaces like rooftops, cars or other supporting structures, the engineers say.
By growing nanowires directly on an untreated electrode surface, you can start thinking about incorporating millions or billions of nanowires in a single device. I think this is where the field is eventually going to end up, said Novotny. But I think we are at least a decade away from this becoming a mainstream technology.
Polymer Solar Cells and Nanowires Meet
|Contact: Daniel Kane|
University of California - San Diego