Thanks to new manufacturing methods, scientists have achieved more than 15% energy conversion on perovskite-type solar cells larger than one square centimeter.
Researchers report that perovskite-type batteries are more than 20% efficient and comparable to traditional silicon cells. But those high-efficiency perovskite batteries are only one-tenth of a square centimeter and are only suitable for laboratory testing, if used when solar panels are too small.
According to NitinPadture, a professor of engineering at Brown University, it is a real improvement to improve the efficiency of a battery of more than one square centimeter by 15%.
Padture says how to maintain high efficiency in larger perovskite batteries has proven to be a challenge, “The problem with perovskites is that when you try to make larger solar films with traditional methods, low efficiency defects It will be exposed.”
The previous manufacturing process of the perovskite battery was established by Zhou Yuanyuan, a graduate student at Padture Labs (not found in the original name, using transliteration, the same below). The perovskite precursor dissolved in a solvent and then precipitated on the substrate. The substrate is then immersed in a second solvent (referred to as an anti-solvent) which selectively dissolves the solvent of the precursor, leaving the ultra-smooth film produced by the perovskite crystals.
The new study, published in the Journal of Advanced Materials, Zhou Yuanyuan (transliteration) and the National Renewable Energy Laboratory postdoctoral researcher Yang Mengjin (transliteration), through a small technique to find ways to increase the size of perovskite crystals. The method is to add an excess of organic precursor, stick to small perovskite crystals, expand them by heating, and treat excess organic precursors by heat treatment.
“The solvent method ensures complete coverage and uniformity,” says Padture. “By covering, we increased the size of the crystal, which allowed us to produce films with fewer defects and higher efficiency.”
A 15% efficiency in this latest product is a good start, Padture said, but there is still room for improvement. Researchers using this or similar methods will eventually hopefully achieve a 20% to 25% efficiency for large batteries.