More efficient solar cells could be on the horizon
At the University of Texas at Austin, researchers are working on solar technology that has the promise of increasing solar cell efficiency from the current 30% conversion rate, up to over 60%. Scientists have been advancing new research on semiconductor nanocrystals, or quantum dots, that can be used in photovoltaic panels to trap some of the energy lost as heat when sunlight strikes the panels.
As reported in this week’s Science:
The maximum efficiency of the silicon solar cell in use today is about 31 percent. That’s because much of the energy from sunlight hitting a solar cell is too high to be turned into usable electricity. That energy, in the form of so-called “hot electrons,” is lost as heat. If the higher energy sunlight, or more specifically the hot electrons, could be captured, solar-to-electric power conversion efficiency could be increased theoretically to as high as 66 percent.
The “ultimate solar cell” could be reality when a few steps are achieved by the research scientists. By slowing down the cooling rate of hot electrons, additional energy from them can be harvested and used. That’s where the quantum dots come into play.
Semiconductor nanocrystals operate to slow the cooling of hot electrons. As shown in the image above, hot electrons may be moved from selenide nanocrytals to an electron conductor created from titanium dioxide.
Much more solar power research and engineering is needed before a 66% efficient solar cell becomes reality, however. Importantly, researchers need to be able to connect to an electrical conducting wire.
Quite simply, we want to capture most of the energy of sunlight. That’s the ultimate solar cell.
With these new solar technology advances, the research group firmly believes we could be using 100% solar energy instead of any fossil fuels within 50 years!
Tags: quantum dots, semiconductor nanocrystals, silicon solar cell, solar cell efficiency, solar power research, solar technology, titanium dioxide, ultimate solar cell
