出典:Wikipedia
出典:『Wikipedia』 (2010/12/06 19:15 UTC 版)
Quantum efficiency (QE) is a quantity defined for a photosensitive device such as photographic film or a charge-coupled device (CCD) as the percentage of photons hitting the photoreactive surface that will produce an electron–hole pair. It is an accurate measurement of the device's electrical sensitivity to light. Since the energy of a photon depends on (more precisely, is inversely proportional to) its wavelength, QE is often measured over a range of different wavelengths to characterize a device's efficiency at each photon energy. Photographic film typically has a QE of much less than 10%, while CCDs can have a QE of well over 90% at some wavelengths.