Therefore, thin, flexible, lightweight solar cells Imagine that they can be placed on virtually any material or surface, his hat, shirt, or smart phone, or even including a sheet of paper or a helium balloon .
Researchers at MIT have now demonstrated such a technology: thin, lightweight solar cells ever created. This is a commercial product, although it can take years to develop a laboratory proof of concept could help power the next generation of portable electronic devices that suggests a new approach for making solar cells.
New action in the Journal of Organic Electronics, MIT professor Vladimir Bulovic, research scientist Annie Wang, and is described in a paper by doctoral student Joel Jean.
Bulovic, protection for innovation and support Fariborz Christ MIT Associate Dean Professor of Emerging Technologies, the new strategy is the key to solar cell, substrate for (1990), and save the environment the overcoating is to say in the process. Built on the substrate location and, during construction, to be clear handled, or removed visibility can degrade cell performance for such dust or other contaminants from the space that never need to minimize .
Bulovic SAIC "inventive step sensation as your device, you can move the development of the substrate at the same time".
In this initial proof of concept, both the substrate and the team overcoating, and primary light is referred to as DBP absorption layer using a flexible organic material such as a polymer called parylene. Parylene is implanted biomedical devices and widely available as a commercial plastic coating used to protect printed circuit boards from environmental damage. The entire process takes place at room temperature and in a vacuum chamber without the use of any solvents, unlike traditional solar cell manufacturing, which requires high temperatures and harsh chemicals. In this case, using both the substrate and the vapor deposition techniques are "large" solar cell.
A process, many materials
The specific choice of materials gives the team just on the left, and the key innovation is that the line substrate manufacturing process. Different materials can be substituted for organic layers used in the initial test, can be used for substrate and encapsulation layers, and different types of thin film solar cell materials including quantum dots or perovskites ,.
But already, the team has ever made the thinnest and lightest full solar cells, he says. To demonstrate how thin and lightweight cells, researchers bubble without popping, wrapped in a cell on top of a soap bubble.can blow up, "Jane losing the advantages of said substrate forming line.
, In the case of glass - similar to a flexible parylene film, kitchen cling wrap, but only one-tenth as thick, the first content stored on a sturdier. Figuring out how to cleanly define the thin material of glass has spent many years working with a major challenge, Wang, who parylene to separate.
Researchers using up after completion of the parylene / solar cell / parylene network stack of the production process, made of flexible film frame. About two micrometers thick - - the ultimate ultra-thin, flexible solar cells, substrate and including overcoating, only one fiftieth of one-thousandth the thickness of a human hair and glass side or the thickness of the solar cells on substrates yet the change in his glass as effectively as their counterparts based on electricity only.
No miracles needed
"We put our careers in a vacuum system up and then we collect everything, and then peel the whole thing," Wang explained. Bulovic like most new inventions sad, it all seems very simple - once it has been. But the development of techniques to make the process work required years of effort.
Since the network used a glass for solar cells, genes "It could be anything. You, takes place under almost any material can be used" processing such benign conditions. For example solar cell substrate and can be deposited directly on fabric or paper.
In this demonstration solar cell device, because of its low weight, it is not particularly effective, its strength-to-weight ratio between the highest success. It is important for applications where weight or high-altitude helium balloon is used for research, such as the space is important. About 400 times more - a typical silicon-based solar modules, whose weight is dominated by a glass cover, while about 15 watts of power per kilogram of weight can produce new cells already grams per 6 watts has demonstrated a production.
"It is not so light that you might not know it, on your shirt or your notebook," said Bulovic. "These cells can be an add-on to existing structures."
Still, it is early laboratory scale, and in a manufacturable product will take time to develop, the team says. But the commercial success may be uncertain in the short term, this can open new applications for solar energy in the long run. "We have worked with the concept of a proof," said Bulovic. The second question is how many miracles, seems to place the extension "We think it's a lot of hard work ahead, but likely needed no miracles."