Spherical Solar Cells That Capture More Light
An idea developed by scientists from the University of Illinois is spherical solar cells which are deemed to be able to capture more light than their flat counterparts.
The flatness of solar panels is one problem researchers are working on overcoming since it's a big limiting factor to the panels' capacity to harness light. In order to achieve angles needed to capture light as the sun travels across the sky, various technologies have come to fruition such as solar trackers, which are systems designed to follow the path of the sun. Another idea developed by scientists from the University of Illinois is spherical solar cells which are deemed to be able to capture more light than their flat counterparts. Achieving this shape for solar cells has been difficult to achieve. The researchers had to devise a way for the cells to self-assemble in order to save costs related to production.
MIT's Technology Review writes:
"Instead of a big slab of semiconductor fitted with concentrating lenses and motors to move it around, we want to make compact cells that still have a significant power output," says Ralph Nuzzo, professor of chemistry at the University of Illinois at Urbana-Champaign.
The solar cells start as flat sheets like conventional cells, but their underlying 3D structure allows them to self-assemble into a sphere. The sheets are made of very thin, high-quality silicon wafer that's treated with conventional lithography. These sheets are first cut into flower-shaped pieces taped with a piece of glass on the inside that serves as a placeholder for the cells to retain their shape later on. Water is subsequently dropped into the flower-like structure; the surface tension brought about by the water's evaporation pulls the structure taut to form a sphere. Current prototype of the material has a mere 1 percent in efficiency, but the team is positive the technique used for its production could be applied to other materials; hopefully something that could lead to more efficient cells.