A
detector in which a photon interacts with a solid surface, which is called the photocathode, or a gas, releasing a photoelectron. This process is called the
external photoelectric effect. The photoelectrons are collected by an electrode at positive
electric potential, i.e. the
anode.
Source:
PAC, 1995, 67, 1745
(Nomenclature, symbols, units and their usage in spectrochemical analysis-XI. Detection of radiation (IUPAC Recommendations 1995))
on page 1752