
Looking Back to Light the Future 41
Prize in 1921 was his interpretation of the external photo-effect, the
“emission of electrons” by the action of radiation. But this was not
yet the interpretation of photovoltaics. As already mentioned, that
also has to do with charge separation of the light-induced electrons
by an internal field effect inside the semiconductor.
There was a time when electron emission found important
industrial applications: one should keep in mind that long before
semiconductor chips acquired the role they have today—the
transistor was developed only in 1954—the key component of
electronics was the vacuum tube. Its operation is based ...