Dark current

Dark current is the constant response exhibited by a receptor of radiation during periods when it is not actively experiencing radiation. It may refer to:

• Dark current (biochemistry) : The depolarizing current, carried by Na⁺ ions, that flows into a photoreceptor cell when unstimulated.
• Dark current (physics): The relatively small electric current that flows through a photosensitive device when no photons are entering the device.
• Dark current (chemistry) : The constant response produced by a spectrochemical receptor, in the absence of radiation.