Solar-powered calculator
Solar powered calculators are hand-held electronic calculators powered by solar cells mounted on the device. They were introduced at the end of the 1970s.
Amorphous silicon has been used as a photovoltaic solar cell material for devices which require very little power, such as pocket calculators, because their lower performance compared to conventional crystalline silicon solar cells is more than offset by their simplified and lower cost of deposition onto a substrate. The first solar powered calculators were already available in the late 1970s, such as the Royal Solar 1, the Sharp EL-8026, and the Teal Photon.