Organometal trihalide perovskite solar cells with conversion efficiencies of 20.1%

25 April 1954 was a seminal day in the history of research on solar cells. On this date scientists at Bell Labs, Murray Hill, USA, announced the invention of the world’s first practical panel of solar cells for converting sunlight into electricity. The solar cells were made of silicon and had an efficiency of 6 percent—a tremendous achievement even by today’s standards. Notably, the solar cells were used to power a radio transmitter and energize a motor to drive a Ferris wheel—both practical applications of solar cells.