Published on January 17th, 2020 | by Cynthia Shahan0
Opaque To Transparent Solar Photovoltaics — Have Koreans Identified The Ideal Tech To Transform Windows Into Solar Power Producers?
January 17th, 2020 by Cynthia Shahan
CleanTechnica has previously covered transparent, two-layer solar film, but time flies — that was mostly back in 2012 and 2013. At that time, CleanTechnica described such technology as possessing an impressive efficiency conversion of 7.3% — created by researchers at the University of California–Los Angeles at that time. That 2013 figure was achieved by doubling the transparent solar cell efficiency the researchers had previously achieved.
Essentially, the story pointed out that the development made possible solar film that is adaptable to windows, buildings, sunroofs, electronics displays, etc. — “harvesting energy while still at the same time allowing light to pass through and visibility/transparency to be maintained.”
Solar-skinned buildings are incredibly utilitarian and beautiful. So, the idea has been popular. Immediately, I think of Copenhagen International School — Nordhavn, one of the astoundingly beautiful ones. Hopefully more developments in transparent photovoltaics will offer more light and solar combinations.
Though, increasing transparency out of natural opaque crystalline silicon is not a simple endeavor. The positive news is that, more recently, Korean researchers have again optimized the energy production from this tech, and this time achieved a transparent material of colored hue.
A scientific journal article titled “Neutral-Colored Transparent Crystalline Silicon Photovoltaics,” published in December of 2019 by researchers in Korea, explains the development as an effective and inexpensive strategy to transform solar cells from opaque to transparent.
There are now more means of catching the sunshine (potentially) with transparent solar power technology. Think of it — even in the smaller edges of our daily world could be used for energy capture or “production.”
Science Daily explains that existing transparent solar cells tend to have a reddish hue and lower efficiency. This development entails puncturing tiny holes on crystalline silicon wafers. The fine holes allow light through without coloring. Ingeniously spaced, the holes are spaced so that the human eye is unable to see the pattern.
“My team members concluded that crystalline silicon is the best material to develop the glass-like, high-efficiency, high-stability, and neutral-colored solar cell,” says Kwanyong Seo, of the Ulsan National Institute of Science and Technology (UNIST), co-senior author on the paper along with Seungwoo Lee of Korea University.
“At first thought, it was a crazy idea for all of us. The problem was that crystalline silicon is not transparent, so before us, nobody tried to make transparent crystalline silicon with neutral colors.” Seo explained why there is a growing need for the see-through solar cell. It is an ideal material to turn windows into solar panels.
“Current solar cells need space. On the ground or enough space on the roof,” he says. “But the roof ratio is getting smaller and smaller compared to the window area,” making it hard to capture as much energy as a building needs. “We want to replace current windows,” says Seo.
“There are many things we have to overcome, such as the regulations by law. We also need to have the mechanical stability and strength to apply our device to replace the current window in the building.”
“Silicon substrate is a very popular material in the semiconductor industry,” says Seo. “We believe that this vision can apply to many different applications, such as transparent electronics. It can also be applied to mobile devices as an energy source.”
Featured image: Solar & Light, by Cynthia Shahan for CleanTechnica, from “Bifacial Solar Panels + Solar Trackers — Do They Have A Future? (#CleanTechnica Exclusive, Part 2)“