It is something quite common in physics: Electrons leave a certain material, fly away and are then measured. Some materials emit electrons when they are irradiated with light. These electrons are called photoelectrons. In materials research, so-called Auger electrons also play an important role—they can be emitted by atoms if an electron is first removed from one of the inner electron shells. But now scientists at TU Wien (Vienna) have succeeded in explaining a completely different type of electron emission that can occur in carbon materials such as graphite. This electron emission type has been known for about 50 years, but its cause was previously unclear.
source https://phys.org/news/2020-11-previously-unknown-mechanism-electron-emission.html
