Yongxi Li holds up a sample of a transparent solar cell. Image credit: Robert Coelius, Michigan Engineering Communications & Marketing
In a step closer to skyscrapers that serve as power sources, a team led by University of Michigan researchers has set a new efficiency record for color-neutral, transparent solar cells.
The team achieved 8.1% efficiency and 43.3% transparency with an organic, or carbon-based, design rather than conventional silicon. While the cells have a slight green tint, they are much more like the gray of sunglasses and automobile windows.
Windows, which are on the face of every building, are an ideal location for organic solar cells because they offer something silicon can’t, which is a combination of very high efficiency and very high visible transparency
“Windows, which are on the face of every building, are an ideal location for organic solar cells because they offer something silicon can’t, which is a combination of very high efficiency and very high visible transparency,” said Stephen Forrest, the Peter A. Franken Distinguished University Professor of Engineering and Paul G. Goebel Professor of Engineering, who led the research.
Buildings with glass facades typically have a coating on them that reflects and absorbs some of the light, both in the visible and infrared parts of the spectrum, to reduce the brightness and heating inside the building. Rather than throwing that energy away, transparent solar panels could use it to take a bite out of the building’s electricity needs. The transparency of some existing windows is similar to the transparency of the solar cells Forrest’s group reports in the journal Proceedings of the National Academy of Sciences.
“The new material we developed, and the structure of the device we built, had to balance multiple trade-offs to provide good sunlight absorption, high voltage, high current, low resistance and color-neutral transparency all at the same time,” said Yongxi Li, an assistant research scientist in electrical engineering and computer science.
The new material is a combination of organic molecules engineered to be transparent in the visible and absorbing in the near infrared, an invisible part of the spectrum that accounts for much of the energy in sunlight. In addition, the researchers developed optical coatings to boost both power generated from infrared light and transparency in the visible range—two qualities that are usually in competition with one another.
The color-neutral version of the device was made with an indium tin oxide electrode. A silver electrode improved the efficiency to 10.8%, with 45.8% transparency. However, that version’s slightly greenish tint may not be acceptable in some window applications.
Transparent solar cells are measured by their light utilization efficiency, which describes how much energy from the light hitting the window is available either as electricity or as transmitted light on the interior side. Previous transparent solar cells have light utilization efficiencies of roughly 2-3%, but the indium tin oxide cell is rated at 3.5% and the silver version has a light utilization efficiency of 5%.
Both versions can be manufactured at large scale, using materials that are less toxic than other transparent solar cells. The transparent organic solar cells can also be customized for local latitudes, taking advantage of the fact that they are most efficient when the sun’s rays are hitting them at a perpendicular angle. They can be placed in between the panes of double-glazed windows..
Forrest and his team are working on several improvements to the technology, with the next goal being to reach a light utilization efficiency of 7% and extending the cell lifetime to about 10 years. They are also investigating the economics of installing transparent solar cell windows into new and existing buildings.
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Transparent solar cells
- Industrial Solar: SolarSpring sells MD Lab to Khalifa University, Abu Dhabion November 20, 2020 at 3:34 am
SvD Näringsliv - nyheter inom ekonomi och näringsliv, aktier och börs. Bevakning av internationella affärer och marknader. Motor- och IT-nyheter.
- New solar window tech from Australian startupon November 20, 2020 at 2:53 am
Australia's ClearVue wants to push ahead with the development of its transparent solar glass technology. Construction is now beginning on a commercial-scale trial project.
- New Study Could Help Create Improved Glasses for Smart Device Touchscreenson November 17, 2020 at 7:24 am
Sophisticated electron spectroscopy and computer simulations have been used by a team of researchers from the Institute of Industrial Science at The University of Tokyo to gain better insights into ...
- Novel transparent solar cells boost efficiency beyond limitson November 11, 2020 at 10:28 pm
Solar power has shown immense potential as a futuristic, 'clean' source of energy. Technologists have been looking for ways to advance the current solar cell technology. Now, scientists have put forth ...
- Growing specialty crops under solar panels shows promiseon November 9, 2020 at 4:00 pm
CSU's Agricultural Research Development and Education Center has seen promising results when growing specialty crops under solar panels.
Go deeper with Google Headlines on:
Transparent solar cells
Go deeper with Bing News on:
Transparent solar cell windows
- The Energizer – Volume 78on November 11, 2020 at 4:00 pm
Biological Batteries Could Take the Spotlight From Solar and Wind Bioo Arkyne Technologies has committed to bringing to market batteries that generate and store energy from soil by t ...
- Novel transparent solar cells boost efficiency beyond limitson November 10, 2020 at 4:00 pm
Solar energy has shown enormous potential as a futuristic, ‘clean’ energy source. Technologists have been looking for ways to advance current solar cell technology. Now scientists have developed an ...
- Scientists design novel transparent solar cells using thin silicon filmson November 2, 2020 at 10:17 pm
For example, solar cells could possibly be integrated into windows, vehicles, cellphone screens, and other everyday products. But for this, it is important for the solar panels to be handy and ...
- 'Transparent solar cells' can take us towards a new era of personalized energyon November 2, 2020 at 3:44 pm
Solar power has shown immense potential as a futuristic, 'clean' source of energy. No wonder environmentalists worldwide have been looking for ways to advance the current solar cell technology.
- 'Transparent solar cells' can take us towards a new era of personalized energyon November 2, 2020 at 1:50 pm
Today, the imminent climate change crisis demands a shift from conventionally used fossil fuels to efficient sources of green energy. This has led to researchers looking into the concept of ...