Imagine a smart credit card that not only stores electronic money and records your transactions but also has its own energy source. Or a sun roof that delivers electricity to your car battery. Imagine each powered by flexible, ultrathin, see-through solar panels.
These scenarios may not be far off, thanks to a photovoltaic cell production process unveiled by Toshiba scientists in May at the 16th European Photovoltaic Solar Energy Conference and Exhibition in Glasgow, Scotland. The Toshiba design is an improvement to the Graetzel cell, a new type of solar panel that relies on titanium dioxide nanocrystals coated with a dye. When struck by light, the dye “injects” energized electrons into the semiconducting titanium, which generates electrical power. Graetzel cells’ advantages over conventional silicon solar panels include transparency, low materials costs and the ability to operate efficiently under cloudy skies.
Earlier Graetzel designs, however, mostly relied on a liquid electrolyte to replenish the dye with electrons; this proved impractical because of the risk of leakage. Toshiba is the first to succeed in encapsulating liquid electrolyte in a durable solid-a “cross-linked” gel that can withstand temperatures of up to 120 C.
Shuzi Hayase, chief research scientist at Toshiba’s Power Supply Materials & Devices Laboratory in Kawasaki, says the cells achieve a respectable 7.3 percent solar-energy conversion efficiency and should be easy to manufacture. “We do not need expensive production lines and sophisticated vacuum systems currently employed in the manufacture of silicon-based cells. The new cells could be manufactured by [silk-screen] printing technologies.”
According to Michael Graetzel at the Swiss Federal Institute of Technology, who invented the basic cell design in the early 1990s, the Toshiba development is “a very important step forward” towards simplifying dye-based cell production. During the next decade, he says, the technology should find its first uses in low-power applications such as sun-powered timepieces (watch manufacturer Swatch already has a prototype) and price scanners. At least seven companies in Japan, Europe and Australia are also developing improved Graetzel cells that may ultimately grace cellular phones, laptop computers and windows in energy-efficient homes.
Anti-aging drugs are being tested as a way to treat covid
Drugs that rejuvenate our immune systems and make us biologically younger could help protect us from the disease’s worst effects.
These materials were meant to revolutionize the solar industry. Why hasn’t it happened?
Perovskites are promising, but real-world conditions have held them back.
The baby formula shortage has birthed a shady online marketplace
Desperate parents just want to feed their babies. They’re having to contend with misinformation, price gouging, and scams along the way.
I tried to buy an Olive Garden NFT. All I got was heartburn.
Our newest issue spells out what you need to know about the dizzying world of digital money.
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.