Researchers Find a Novel Way to Potentially Double Solar Cell Efficiency
Researchers looking into new and sustainable energy have achieved a breakthrough in solar cell technology by reporting the development of a “green antenna” to potentially double the efficiencies of certain solar cells and significantly, make them more affordable.
Solar energy is a proven, inexhaustible source of energy and is slowly findings its way into communities. While installations of solar cells are an upward trend, the implementation of the technology is growing at a slow pace due to certain disadvantages. Initial costs are expensive and aren’t recouped for years, even with the best-subsidized neighborhoods and solar technology is, currently, notoriously inefficient. In proving a much-welcome shot in the proverbial arm for more adopters of solar technology, the development of a new “antenna” as an add-on to certain existing solar cells could potentially double the cells’ efficiency. The researchers behind it also claim that they intend to make consumer-end solar technology, more affordable.
The researchers will be presenting their work at the 250th National Meeting & Exposition of the American Chemical Society (ACS) in Boston, today.
Solar Cell Efficiency Gets a Level Up
Solar energy helps produce electric current when sunlight is harvested from a broad spectrum of wavelengths, explains Challa V. Kumar, Ph.D., and a part of the research team at the University of Connecticut.
“Most of the light from the sun is emitted over a very broad window of wavelengths,” says Kumar. “If you want to use solar energy to produce (an) electric current, you want to harvest as much of that spectrum as possible.”
However, silicon solar cells that are often purchased by consumers aren’t entirely efficient in the blue area of the light spectrum. To overcome this inherent hurdle, Kumar and his team of researchers built an antenna that collects those unused blue photons before proceeding to convert them into lower energy photons. With this solution, silicon cells can then turn the lower energy photons into electric current, improving the cell’s efficiency.
Many groups around the world are working hard to make this kind of antenna, and ours is the first of its kind in the whole world – boasts Kumar.
Commercially used solar cells that are available in the market today are only about 11 to 15 percent efficient. While they do an able job of converting light from 600 to 1,000 nanometers (nm) into electric current, they fail at the 350 to 600 nm range. Higher-end panels routinely reach 25 percent efficiency, but are very expensive and are unaffordable to most end-users. Certain lab prototypes that are currently being tested can scale, even higher efficiencies, but aren’t viable as an affordable product.
The process of converting unused portions of the light spectrum to the wavelengths acceptable by solar cells is equally expensive, but Kumar and his team found a workaround by using organic dyes.
Dye molecules turn happy when introduced to photons in light, which could then, under the right factors, help relax and emit less frenetic but more silicon cell-friendly photons. In order to get the dye molecules to work together, it’s required that they are wrapped individually and densely in order to adhere to certain quantum mechanics. Here’s how the research team tackled the issue:
- The dyes were embedded inside a protein-lipid hydrogel after mixing them together, warming them first and then cooling them down to room temperature.
- This accelerated the material into wrapping around individual dye molecules, whilst still keeping them separated.
- Now packed densely, the outcome is a thin membrane of pinkish film that can be coated on top of a solar cell.
“It’s very simple chemistry,” Kumar says.
It can be done in the kitchen or in a remote village. That makes it inexpensive to produce.
Moreover, these antennas are also made exclusively from biological and non-toxic materials. They’re even edible, in theory. “Not that you would want to eat your solar cells, but they should be compostable so they won’t accumulate in the environment,” Kumar adds.
Kumar and his team are actively working with a Connecticut-based company to figure out ways in implementing the artificial ‘green’ (and edible) antenna to commercially available solar cells. Furthermore, they are also trying to use the highly-versatile hydrogel for white light-emitting diodes and drug delivery, confirms Kumar.
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