A team of scientists at the Massachusetts Institute of Technology (MIT) have made the thinnest and lightest solar cells known to man.
The technology, which uses small flexible cells, could be used to power a new generation of personal electronic devices. The cells are just 1.3 micrometers thick, the equivalent to a soap bubble, and have a surface density of 3.6 grams per square meter.
MIT researchers make incredibly light and thin solar cells
MIT professor and associate innovation dean Vladimir Bulovi? described the process behind the technology in the April edition of Organic Electronics, along with researcher Annie Wang and doctoral student Joel Jean. The organic cells were made by growing a parylene-C polymer substrate film in a vacuum, giving scientists solar units that produce as much energy as traditional glass cells.
As the cell, substrate and coating are grown together in the laboratory using a single process, development was streamlined and the cells are less exposed than if individual components were created separately.
“The innovative step is the realization that you can grow the substrate at the same time as you grow the device,” Prof. Bulovi? said in a MIT news release. Another boon is that the process works at room temperature without the need for solvents and chemicals. This is a major step forward from the solar-cell production techniques used today.
New technique could bring solar cells to a variety of new surfaces
The new method means that cell components grow in a vacuum at room temperature, using only the vapor deposited by polymer precursors. These eventually react and settle to fuse the parts of the cell together.
“It’s a very versatile and widely used manufacturing process,” MIT associate professor John Hart said of the vapor system, calling it “a very general process that can be tailored to many different applications,” including solar cell formation.
At this stage the development of the solar cells has been called a proof-of-concept by the researchers. The process could use different materials should the method increase in popularity, but the cells developed by scientists are already functional.
Further research required before technique is commercially viable
Their output is around 6 watts per gram, around 400 times more than glass solar cells despite the fact that they are only 1/1000th the thickness. “If you breathe too hard, you might blow [them] away,” Mr. Jean said.
During their research the cells were placed on glass, but the simple collection process means that the cells could be placed on many different materials including rubber and fabric. “It could be so light that you don’t even know it’s there, on your shirt or on your notebook,” Mr. Bulovi? said in a news release. “These cells could simply be an add-on to existing structures.”
As it stands the team has successfully demonstrated that the vapor and polymer process is viable, but moving it from the laboratory to commercial production will mean more work is necessary. However if scientists can do so we may see solar power used in new areas. Bulovi? is confident that the method will be used for commercial applications in the future. The possibilities are almost endless.
“How many miracles does it take to make it scalable?” he said. “We think it’s a lot of hard work ahead, but likely no miracles needed.”