The development of cheaper and more efficient solar cells is crucial for the advancement of solar energy, so scientists are looking into the production of new technology. Perovskite solar cells, a cheaper form of technology, is quickly looking like the replacement for its more expensive rival, silicon cells. Here is an excerpt:
The word “perovskite” refers to the type of material the cell is made out of. A perovskite material has a special type of crystal structure — calcium titanium oxide is one example, but other materials can have similar structures and be referred to as perovskites.
Around 2009, researchers started trying to make solar cells using perovskite materials, said Nitin Padture, director of the Institute for Molecular and Nanoscale Innovation and professor materials science at Brown University. And while the first of these experiments only achieved an efficiency of less than 5 percent, scientists have since improved them drastically. Now, they’re recognized by some experts as one of the most promising innovations in solar research.
The major appeal of perovskite solar cells is that they’re cheap — “much cheaper than something like silicon,” Padture explained. High-quality silicon crystals must be made at high temperatures using very precise processes, he said. Perovskite cells, on the other hand, can be made at nearly room temperature using simpler methods, so production is not so costly.
Of course, lower costs don’t mean much if the cells can’t compete with the efficiency of traditional silicon cells. But in the lab, at least, scientists have succeeded in producing perovskite solar cells with efficiency levels comparable to those of commercially used silicon cells — upwards of 20 percent.
Perovskite solar cells are in no way ready for commercial use yet — Padture predicts that point is still at least 5 to 10 years away — but the early promise has led researchers to explore a number of different applications for the cells. On the one hand, if their costs and efficiency levels become competitive enough, they could be used alone in solar arrays in the same way that silicon solar cells are widely used today. However, some researchers believe the real future of solar energy lies in a new experimental technique that layers perovskite solar cells on top of silicon cells in order to maximize their total efficiency.
The reason this technique seems promising is because silicon cells capture sunlight at slightly different wavelengths than perovskite materials, said McGehee, the Stanford researcher. So if you put them together, they’re able to take advantage of a bigger segment of the spectrum than either would alone.