Solar energy has come a long way in recent years, with advancements in technology leading to more efficient and cost-effective solar cells. However, there’s still room for improvement, as current solar cells only capture about 27% of the energy from the sunlight that hits them. This is close to the theoretical limit for single-material solar cells, but researchers are exploring new ways to boost efficiency even further.
One promising approach is the development of tandem solar cells, which combine multiple materials to absorb a wider range of wavelengths from the sun’s energy. A team of physicists and engineers at the Technical University of Denmark has recently made progress in this area by creating a selenium-silicon tandem solar cell.
Selenium, a semiconducting material with different photon-absorbing properties and a wide bandgap, was once used in solar cells before silicon became the standard. The researchers decided to revisit selenium, pairing it with silicon to create a more efficient tandem cell.
To make the cell, they started with a silicon base, added some oxide layers, and then topped it off with a thin film of selenium. When tested under sunlight, the cell generated 1.68 volts of electricity and had a conversion efficiency of 2.7%. While this may not seem impressive at first glance, the researchers believe that with some improvements to reduce resistance and minimize voltage loss, the efficiency could be increased by a factor of 10.
In fact, their calculations suggest that with further refinement, the selenium-silicon tandem cell could potentially reach an efficiency of around 40%. This would be a significant breakthrough in solar cell technology, as it would allow for much more energy to be generated from the same amount of sunlight.
If achieved, this increased efficiency could have far-reaching implications for the adoption of solar energy. It would make solar power more cost-competitive with other energy sources and reduce the amount of land needed for solar farms. Additionally, it could accelerate the transition away from fossil fuels, helping to mitigate the effects of climate change.
Of course, there’s still work to be done to turn this promising concept into a practical reality. The researchers will need to continue refining and optimizing the selenium-silicon tandem cell to reach the projected efficiency levels. However, their initial success, as reported in the journal PRX Energy, is an exciting step forward in the quest for more efficient and sustainable solar energy.
As solar technology continues to advance, it’s important to keep an eye on developments like this selenium-silicon tandem cell. With ongoing research and innovation, we may be able to unlock even more of the sun’s potential, paving the way for a cleaner, greener future.
