Perovskites, a class of semiconductor material still in its infancy, makes solar cell that reaches the 15% conversion milestone. Researchers started using organometal trihalide perovskite semiconductors (which have the formula (CH₃NH₃)PbX₃, where Pb is lead and X can be iodine, bromine or chlorine) in solar cells a few years ago. Since then, the performance of perovskite-containing solar cells has skyrocketed. The characteristics of these materials such as high carrier mobility and relatively longer lifetime of the carrier enable the photo-generated electrons and holes moving a sufficient distance to be collected by an external circuit current, instead of the battery losing its energy in the form of heat.

The fact that multiple teams are making such rapid progress suggests that the perovskites have extraordinary potential, and might elevate the solar-cell industry to new heights. The perovskites has three advantages compared to other semiconductor materials as the follows:

1. High energy conversion efficiency. Because perovskites generate a higher voltage (1 volt) than silicon, the tandem cell would be more efficient than a silicon cell. It is hard to estimate how efficient the perovskite solar cells could be, but it seems likely that their efficiency will continue to climb. It is even possible that perovskites will emerge as the champion material for solar cells.
2. Lower costs. Perovskites could be printed on top of silicon in a way that would add little to the manufacturing cost. A rough calculation suggests that the performance of currently available, commercial solar cells could be boosted by 25%, and would require only minor modifications to existing factories.
3. Long-term stability. The results of preliminary tests performed on short timescales are promising, but some researchers remain concerned that a water-soluble material that can be sublimed at a low temperature (as perovskites can) will lack the rock-like stability that enables silicon solar cells to last for more than 25 years.

Further breakthroughs in perovskite solar cells can certainly be expected in the months and years to come. The history of these materials may be brief, but their performance so far suggests that their role in the solar-cell field will be anything but. (Nature, 2013,501,323; Nature, 2013,342,344; Nature,2013, 501,396; Nature, 2013, 499, 316)