MIT's new all-carbon solar cell harnesses infrared light

[daaron]

http://web.mit.edu/newsoffice/2012/infrared-photovoltaic-0621.html

About 40 percent of the solar energy reaching Earth’s surface lies in the near-infrared region of the spectrum — energy that conventional silicon-based solar cells are unable to harness. But a new kind of all-carbon solar cell developed by MIT researchers could tap into that unused energy, opening up the possibility of combination solar cells — incorporating both traditional silicon-based cells and the new all-carbon cells — that could make use of almost the entire range of sunlight’s energy.

“It’s a fundamentally new kind of photovoltaic cell,” says Michael Strano, the Charles and Hilda Roddey Professor of Chemical Engineering at MIT and senior author of a paper describing the new device that was published this week in the journal Advanced Materials.

The new cell is made of two exotic forms of carbon: carbon nanotubes and C60, otherwise known as buckyballs.

[PoliticAverse]

1. "the early proof-of-concept devices have an energy-conversion efficiency of only about 0.1 percent"

About 200 times less efficient than conventional solar cells.

[daaron]

2. And? nt

[Confusious]

5. 100 watts of heat means 1 watt of power

maybe if you covered a house, you could get enough to run a coffee maker.

Or in other words, it ain't gonna save the world anytime soon.

[krispos42]

3. What can be done, can be done again.

What can be done again, can be improved.

[DetlefK]

4. There are deeper issues than efficiency: scratches and dust-seeds on the surface.

What if you gently touch that surface with your finger?
What about dust-seeds, spores, skin-flakes that fly through the air in a natural environment?
How about scratches and abrasion by dust / fine sand / fingernails?
What about flies landing on it?
What about bird-shit?

You cannot cover these CNT-/C60-solar-cells with ordinary glass: Glass is transparent for visible light, but not for infra-red.

For these solar-cells to become applicable, you first have to find a cover-material that is cheap, can be mass-produced and is transparent for infra-red (with transparency in the visible spectrum as a bonus).

[DetlefK]

6. Addendum: You could use glass as protective layer, but it would further decrease efficiency.

Cover the solar-cell with glass and put a black heat-absorbing foil on that. The problem is, the glass is now a heat-reservoir (with a leak!) that has to be filled, before the hot glass transmitts the heat to the solar-cells.