MIT pioneers world’s thinnest solar cell

The next step in solar development: cheaper, thinner cells will open up the market

The new solar cells produce up to 1,000 times more power than conventional PV cells. (Source: MIT)

By Nilima Choudhury

Massachusetts Institute of Technology (MIT) researchers have created the world’s ‘thinnest solar cell’. 

The solar cells are one nanometer thick and can deliver 1,000 times more energy per pound than conventional solar cells. However, the efficiency is drastically lower than conventional cells.

Researchers claim they can get around this issue by stacking the cells in layers to improve efficiency.

“Stacking a few layers could allow for higher efficiency, one that competes with other well-established solar cell technologies,” says Marco Bernardi, a postdoc in MIT’s Department of Materials Science.

For applications where weight and cost is a crucial factor – such as in spacecraft, aviation or for use in remote areas of the developing world, where transportation costs are significant – such lightweight cells could already have great potential, said Bernardi.

“It’s 20 to 50 times thinner than the thinnest solar cell that can be made today,” Jeffrey Grossman, the Carl Richard Soderberg associate professor of Power Engineering at MIT adds. “You couldn’t make a solar cell any thinner.”

“It is very hard to provide a figure right now. The clear advantage would be in terms of using significantly less material per unit area, and thus saving both on the material and on installation costs (since the solar cells will be lighter),” says Bernardi.

Researchers claim the cells are also immune to oxygen, ultraviolet radiation, and moisture in the environment.

These are the three killers of long-term stability in conventional solar cells – giving the new ultra-thin designs the additional advantage of eliminating the need for glass covers or standoff mounting, which consumes over half the cost of conventional photovoltaic installations.

Researchers have yet to create prototypes in the lab or to bring this to market.

The next step in this process is to test their formulations in the lab by measuring the efficiency and long-term stability of various formulations and stacking structures.

“In terms of making these solar cells a reality – in the lab, and eventually at the R&D and commercialisation level – there are significant hurdles that need to be overcome,” said Bernardi.

“One of them is certainly cost and ease of fabrication. Silicon and gallium arsenide [currently used to manufacturer solar modules] match the standards required by the semiconducting industry, while these atom-thick materials need further R&D before they can be used commercially. We are fairly close to achieving the first such kind of nanometre-thick solar cell.

“Time will tell,” said Bernardi, “whether we (as a scientific community) will become capable of fabricating large sheets of atom-thick materials and manipulate them at will similar to other conventional semiconductors like silicon and gallium arsenide.”


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