We all want new kinds of power chargers – items that give our smartphones, laptops and other gear juice in easier and more versatile ways. The old conventional charging cable is a nuisance, and other new alternatives, such as Qi wireless charging, are replacing it, where users can just set a device down on a tray or pad and let it soak up the power.
At the same time, governments and businesses are trying to cut down on fossil fuels, and get renewables to the fore. Now, there is a new material on the horizon that could change the way we view solar power. It's called perovskite, and it's a type of mineral that's common and easy to get hold of.
In fact, some people are even thinking that this type of advancement could pave the way for effective wearable solar cells – solar chargers built right into clothes or accessories.
This New Scientist article shows how researchers at the Chinese Academy of Sciences found perovskite could convert 20% of the Sun's energy into electricity, and that using nanotechnology, it can be made into very flexible and versatile solar cells. These scientists coated carbon nanotubes with perovskite and silver, weaving them into cloth, to try to make new wearable solar chargers that could power a generation of new devices.
Perovskite and Silicon: “Tandem” Solar Cells
Another perovskite project has to do with adding this element to an existing silicon layer, which is common in traditional solar panels. For elaborate technical reasons, adding perovskite to silicon layers can allow broader use of solar energy. MIT experts added a thin, semi-transparent layer of perovskite.
The benefits of this breakthrough have to do with the absorption of solar energy.
“Different layers absorb different portions of the sunlight,” says MIT researcher Jonathan Mailoa in a March press release on the new tandem solar cells.
MIT scientists first added a perovskite layer with its own wiring and electrical circuit controls; now, a newer version combines the circuit for both the silicon and the perovskite layer, making it easier to manufacture the tandem cells.
Drawbacks of Perovskite
Although perovskite has potential, it’s not a panacea for solar progress. For one thing, the Chinese scientists were only able to convert about 3% of the solar energy into electricity, and perovskite faces other additional challenges.
One of them, said Mailoa in a recent interview, is the fact that lead is an ingredient in the mineral. It's obviously tricky to produce any kinds of consumer materials with lead, so researchers are trying to come up with good alternatives.
Then there's the chimerical nature of perovskite as a material – multiple teams have found that the stuff degrades quickly when exposed to air and water.
Mailoa explains that the particular perovskite semiconductor best for making solar cells dissolves in water, and will decompose in air. That means these types of solutions will need to be encapsulated, which adds cost and complexity.
“It certainly is an exciting advance, but not good enough yet for wearable technology,” Mailoa said, adding that there are other kinds of solar cells that are more efficient, stable and flexible.
Chinh Pham works for Greenberg Traurig. Pham co-leads the Emerging Technology Practice and is Chair of the firm's nanotechnology practice. He is a registered patent attorney with experience in the strategic creation, implementation and protection of intellectual property rights for high technology and life science clients.
Pham points out that while the tandem solar cells are not yet to the point where they can be more effective than silicon for wearables, down the road, the perovskite-plus-silicon design can have a range of potential applications.
“As more research is done, the combination of perovskite plus silicon may also provide better economics for other electronics applications,” Pham says, citing things like display monitors, imaging appliances, and various kinds of LEDs.
The New Interface
Part of the larger context for the work on perovskite and its use in nanotech is a bold march toward a new kind of physical interface. In the past few years, with evolutions in how to use chemical layers to create displays and transmit signals, new “bendable” interfaces are on their way. Soon, that iPhone “brick” in your pocket may be replicated in a laser display laid right on your arm, or a thin film that can be rolled up or folded into your wallet.
It’s all part of the advanced miniaturization that’s the new frontier, after Moore’s Law shrunk down ENIAC and huge mainframes into tiny smartphones. And it’s an exciting time for IT – now, there’s more indication that these types of designs will help with the renewable energy movement, too!