Edmond Becquerel (1820-1891), French physicist. Becquerel's research included studies of the solar spectrum, magnetism, electricity and optics. His discoveries included the photovoltaic effect in 1839. He also worked on luminescence and phosphorescence. Part of a famous family of scientists, he was the son of Antoine Cesar Becquerel and the father of Henri Becquerel. Illustration published in 1891.