https://doi.org/10.1351/goldbook.V06619
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.