How perovskites can help develop high-efficiency, low-cost solar cells Solar panels. (Image by Michael Mazengarb, Flickr). Researchers at Canada’s McGill University have made a step forward in unlocking the mystery of how perovskites act as semiconductors even when there are defects in the material’s crystal structure. Perovskite is a calcium titanium oxide mineral composed of calcium titanate. Sign Up for the Energy Digest Sign Up The McGill finding is considered crucial for the development of high-efficiency, low-cost solar cells and other optical and electronic devices because perovskite breaks with the limitations posed by other semiconductors, which require stringent and costly manufacturing techniques to produce crystals that are as defect-free as possible.