100 Years of Photoemission

Abstract

With these words, Heinrich Hertz announced in 1887 the discovery of the photoelectric effect. Although he realized that the phenomenon was important, he certainly could not have imagined how fundamental its role in physics was to be over the next 100 years. Even now, many physicists do not completely understand that role. For example, the effect is often, but incorrectly, credited with leading Albert Einstein to the quantization of the electromagnetic field. Photoemission experiments actually made their most important contributions to field quantization after Einstein had formulated the theory, by demonstrating its validity.