Solar-cell fabrics may soon be a reality, thanks to new research from Penn State. For the first time, a silicon-based optical fiber with the ability to be used as a solar cell has been created, and is scalable to a usable size. The new research brings the possibility of flexible, irregular, cloth-like solar cells (woven from the fibers) nearly within reach.
“The team’s new findings build on earlier work addressing the challenge of merging optical fibers with electronic chips — silicon-based integrated circuits that serve as the building blocks for most semiconductor electronic devices such as solar cells, computers and cellphones. Rather than merge a flat chip with a round optical fiber, the team found a way to build a new kind of optical fiber — which is thinner than the width of a human hair — with its own integrated electronic component, thereby bypassing the need to integrate fiber-optics with chips. To do this, they used high-pressure chemistry techniques to deposit semiconducting materials directly, layer by layer, into tiny holes in optical fibers.”
For the new research the same techniques were used to create a crystalline silicon semiconductor fiber that is able to work as a solar cell, which essentially means a fiber that can create electricity from sunlight.
“Our goal is to extend high-performance electronic and solar-cell function to longer lengths and to more flexible forms. We already have made meters-long fibers but, in principle, our team’s new method could be used to create bendable silicon solar-cell fibers of over 10 meters in length,” Badding said. “Long, fiber-based solar cells give us the potential to do something we couldn’t really do before: We can take the silicon fibers and weave them together into a fabric with a wide range of applications such as power generation, battery charging, chemical sensing and biomedical devices.”
Electricity-generating fabrics obviously have an enormous number of possible applications, allowing much greater autonomy from centralized power sources.
“A solar cell is usually made from a glass or plastic substrate onto which hydrogenated amorphous silicon has been grown,” Badding explained. “Such a solar cell is created using an expensive piece of equipment called a PECVD (plasma-enhanced chemical vapor deposition) reactor and the end result is something flat with little flexibility. But woven, fiber-based solar cells would be lightweight, flexible configurations that are portable, foldable and even wearable.”
The woven fibers could simply be connected to electronic devices, easily charging them on the go. “The military especially is interested in designing wearable power sources for soldiers in the field,” Badding added.
Another major advantage of such fabrics would be their ability to use light simultaneously from various different angles, thanks to their flexible nature.
“A typical solar cell has only one flat surface,” Badding said. “But a flexible, curved solar-cell fabric would not be as dependent upon where the light is coming from or where the sun is in the horizon and the time of day.”
Pier J. A. Sazio of the University of Southampton in the United Kingdom and one of the team’s leaders added, “Another intriguing property of these silicon-fiber devices is that as they are so compact, they can have a very fast response to visible laser light. In fact, we fabricated fiber-based photodetectors with a bandwidth of over 1.8 GHz.”
The findings were just published in the online edition of the journal Advanced Materials on December 6th.
Source: Penn State
Image Credits: Badding lab, Penn State University
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