The key to cheap solar power may have been discovered over 150 years ago | ExtremeTech

By Ryan Whitwam on August 9, 2013 at 10:27 am

Improvements in solar powertechnology come at a frustratingly slow pace. There’s abundant freeenergy raining down on the planet every day, but we simply haven’t found a highly efficient way to collect it. Researchers are looking at new materials to improve photovoltaic cells, but one of the most promising of them wasn’t concocted in a lab from exotic nanoparticles, or meticulously designed on the molecular scale — it’s a rock. Well, a particular kind of mineral, but it’s been known about for over 150 years.

Researchers have been divided on how to make solar power viable. Some see giant numbers of cheaper, low-efficiency cells as the best approach. Others believe expensive solar panels that are more efficient will power the future. If research into perovskite-based solar cells works out, both camps might be able to claim victory.

The first samples of perovskite (pictured above) were discovered in the Ural Mountains of central Russia in 1839. It’s an unassuming crystalline organometal, mostly composed of calcium titanate, but no one suspected it had any special properties at the time. It was later found to have light-absorbing properties, and can act as a semiconductor. It first occurred to researchers to try using it in solar cells in 2009. While those early experiments showed only modest results — 3.5% efficiency and poor longevity — the technology has vastly improved in the intervening years.