According to a recent University of Texas (in Austin) press release, solar cells could soon extract twice as many electrons from each photon of sunlight received. This would be achieved using an organic plastic semiconductor material.
Solar cells are, themselves, a semiconductor material which is often printed onto a substrate such as glass or plastic (just to clarify this for you), and they are encased in solar panels for protection.
“Plastic semiconductor solar cell production has great advantages, one of which is low-cost,” said Zhu, a professor of chemistry. “Combined with the vast capabilities for molecular design and synthesis, our discovery opens the door to an exciting new approach for solar energy conversion, leading to much higher efficiencies.”
The maximum theoretical efficiency of the type of silicon solar cell that is usually used today is 31%, and these researchers say that they can achieve a 50% to 100% efficiency improvement.
Much of the electrons received by solar cells from the sun are of the “hot” type and are usually converted into heat in the panel instead of electricity. Capturing the “hot” electronics could facilitate 66% efficiency, which is extremely high for any type of generator.
Zhu and his researchers demonstrated that the hot electrons mentioned could be captured using semiconductor nanocrystals.
There are challenges still, of course. “For one thing,” said Zhu, “that 66 percent efficiency can only be achieved when highly focused sunlight is used, not just the raw sunlight that typically hits a solar panel. This creates problems when considering engineering a new material or device.”
A type of solar power plant that requires concentration in order to function correctly uses gallium arsenide solar panels, which achieve 42% efficiency, which is impressive compared to the 20% efficiency that typical solar cells achieve.
I can’t be sure where exactly this discovery will take solar technology, but surely in the right direction. It is another bit of evidence that suggests that solar cell efficiency and cost will likely continue to improve at a rapid pace.
h/t Think Progress