Perovskite (calcium titanate) cells are a particularly promising new solar technology. Most conventional solar cells use crystalline silicon, but perovskite is the building block material for these new cells. They can be made into stand-alone solar cells or layered on top of silicon solar cells, gathering light that the silicon cells cannot capture on their own. When combined, these solar cells would be more efficient, producing more electricity per photon.
A key benefit of using perovskite instead of silicon is that it is a low-cost material. According to the Wall Street Journal, perovskite solar cells have also made greater strides in efficiency over the past eight years compared to any other kind of solar cell.
To bring perovskite cells into the market, developers must first overcome two weaknesses: perovskite needs to be protected from moisture to maintain high performance levels and perovskite materials currently degrade faster than other competing solar cells, such as crystalline silicon.