1. Quantum sensors

The detectors described in this article are quantum detectors, i.e. they obey the laws of quantum mechanics governing the energy levels accessible to free carriers – electrons or holes – in materials, and the possible energy exchanges between electromagnetic waves and matter. The focus is on photovoltaic detectors, which use the energy of each photon to excite an electron-hole pair in a junction (diode) (see the article Semiconductor sensors [ E 3092 ]), but also, for night vision (§ 3.1), external photoelectric effect detectors, where an incident photon extracts an electron from a material (photocathode)...