A vacuum tube containing a photosensitive area, or target, and an electron gun to read the signal from the target. The silicon target consists of a two-dimensional array of Si-photodiodes having a common cathode and isolated anodes. irradiation of the target causes the production of electron-hole pairs which, by recombination, leads to a depletion of the surface charge.
PAC, 1995, 67, 1745. 'Nomenclature, symbols, units and their usage in spectrochemical analysis-XI. Detection of radiation (IUPAC Recommendations 1995)' on page 1757 (https://doi.org/10.1351/pac199567101745)