Stanford and Princeton Have Solar Breakthroughs

It’s not often that you can talk about two solar breakthroughs back to back. But, researchers at both universities, Stanford and Princeton, have turned the light on with new solar technology.

Stanford researchers have developed solar cells made completely out of carbon. This has the potential of drastically reducing the price of the cells since no silicon is used and thus no competition with the semiconductor industry for materials.

According to Stanford, “The all-carbon solar cell consists of an active layer of C60 (a form of carbon) and carbon nanotubes sandwiched between conductive and transparent n-type doped cathode and graphene-based anode which allows for the penetration of sunlight to excite electrons.”

Now, Princeton has gone another direction with their solar breakthrough. They have dramatically increased the efficiency of their solar cells. The Princeton researchers are using a nanomesh (sandwich) to trap the light that would typically reflect off of conventional cells.

According to Princeton, “With their new metallic sandwich, the researchers were able to address both problems. The sandwich — called a subwavelength plasmonic cavity — has an extraordinary ability to dampen reflection and trap light. The new technique allowed Chou’s team to create a solar cell that only reflects about 4 percent of light and absorbs as much as 96 percent. It demonstrates 52 percent higher efficiency in converting light to electrical energy than a conventional solar cell.

“That is for direct sunlight. The structure achieves even more efficiency for light that strikes the solar cell at large angles, which occurs on cloudy days or when the cell is not directly facing the sun. By capturing these angled rays, the new structure boosts efficiency by an additional 81 percent, leading to the 175 percent total increase. Chou said the system is ready for commercial use although, as with any new product, there will be a transition period in moving from the lab to mass production.”

So, you can see that two top universities on opposite coasts have developed two different breakthroughs in solar energy. For a green tech guy like me, on a day that the Mayan’s said the world is supposed to end, this is quite a holiday present.