14 DAY TRIAL // A team of scientists from the Massachusetts Institute of Technology (MIT) announces the development of a new method for producing silicon wires inexpensively and straightforward. This could translate practically into the creation of new generation of sensors, solar cells and batteries.
One of the most important areas of research in materials science lately has been the creation of microwires, which are in essence silicon tubes about the thickness of a human hair.
They can be used for a wide array of applications, including the creation of solar cells that can harvest light more effectively than any existing technology. Solar energy-harvesting devices made with these microwires also produce more power over the same surface than conventional methods.
In the new study, investigators were able to develop a new approach to creating these structures. Their method is cheaper and easier to implement that that required to produce thin wafer silicon crystals/
Working in collaboration with colleagues from the Pennsylvania State University (Penn State), the experts managed to achieve a way of building these microwires in bulk, at scales suitable for industrial applications.
The method also allows those in charge of the manufacturing process to ensure the control of individual wires. This means that commercial applications using these materials will soon become possible.
According to MIT professor of mechanical engineering Tonio Buonassisi, other methods of producing such silicon nanowires exist, but they are very limited in many regards. The expert is also the coauthor of a new study detailing the work, which appears in the latest issue of the scientific journal Small.
The other approaches do not rely offer too much control over the exact sizes and spacing of the wires being produced, and also require numerous manufacturing steps. Additionally, they can only be used on flat surfaces.
Despite its simplicity, the new approach is more elegant and more precise than its predecessors. Experts at MIT and Penn State say that their approach could theoretically work on curved, 3D surfaces too.
“The new method involves heating and intentionally contaminating the surface of a silicon wafer with copper, which diffuses into the silicon. Then, when the silicon slowly cools, the copper diffuses out to form droplets on the surface,” an MIT statement reads.
“What's really new here is the method of producing those liquid metal droplets,” Buonassisi explains.
His work was supported by the US Department of Energy, the Chesonis Family Foundation and the US National Science Foundation (NSF). Co-authors included Vidya Ganapati, PhD student David Fenning, postdoctoral fellow Mariana Bertoni, and research specialist Alexandria Fecych, all at MIT.
Postdoctoral researcher Chito Kendrick and professor Joan Redwing, both of Penn State, were also involved in the research.