Edmond Becquerel

Alexandre-Edmond Becquerel (1820 to 1891) was a French physicist who studied the solar spectrum, magnetism, electricity and optics. At the age of 19, while experimenting in his father's laboratory, he placed silver chloride in an acidic solution connected to platinum electrodes and found that light produced a voltage and current, the photovoltaic effect that is the operating principle of the solar cell and is also called the Becquerel effect. In 1840 he found that silver halides become sensitive to red and yellow light in proportion to their exposure to blue, violet and ultraviolet light, and in 1848 he produced colour photographs of the solar spectrum, though they could not be stabilized. He also worked on luminescence and phosphorescence. The son of Antoine Cesar Becquerel and father of Henri Becquerel, he succeeded his father at the Museum national d'histoire naturelle, taught at the Agronomic Institute in Versailles in 1849 and received the chair of physics at the Conservatoire des arts et metiers in 1853.