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In [[physics]] and in [[electronic engineering]], '''dark current''' is the relatively small [[electric current]] that flows through [[photodetector|photosensitive devices]] such as a [[photomultiplier tube]], [[photodiode]], or [[charge-coupled device]] even when no [[photon]]s enter the device; it consists of the charges generated in the detector when no outside radiation is entering the detector. It is referred to as [[reverse bias]] [[leakage current]] in non-optical devices and is present in all [[diode]]s. Physically, dark current is due to the random generation of [[electron]]s and [[electron hole|holes]] within the [[depletion region]] of the device.
{{Short description|Weak electric current generated by photosensitive devices in pure darkness}}In [[physics]] and in [[electronic engineering]], '''dark current''' is the relatively small [[electric current]] that flows through [[photodetector|photosensitive devices]] such as a [[photomultiplier tube]], [[photodiode]], or [[charge-coupled device]] even when no [[photon]]s enter the device; it consists of the charges generated in the detector when no outside radiation is entering the detector. It is referred to as [[reverse bias]] [[leakage current]] in non-optical devices and is present in all [[diode]]s. Physically, dark current is due to the random generation of [[electron]]s and [[electron hole|holes]] within the [[depletion region]] of the device.<ref>{{Cite journal |last=Allam |first=J. |last2=Capasso |first2=F. |last3=Alavi |first3=K. |last4=Cho |first4=A.Y. |date=January 1987 |title=Near-single carrier-type multiplication in a multiple graded-well structure for a solid-state photomultiplier |url=https://ieeexplore.ieee.org/document/1487081/ |journal=[[IEEE Electron Device Letters]] |volume=8 |issue=1 |pages=4–6 |doi=10.1109/EDL.1987.26531 |issn=0741-3106}}</ref>

The charge generation rate is related to specific [[crystallographic defect]]s within the depletion region. Dark-current [[spectroscopy]] can be used to determine the defects present by monitoring the peaks in the dark current histogram's evolution with temperature.


Dark current is one of the main sources for noise in [[image sensor]]s such as charge-coupled devices. The pattern of different dark currents can result in a [[fixed-pattern noise]]; [[dark frame subtraction]] can remove an estimate of the mean fixed pattern, but there still remains a temporal noise, because the dark current itself has a [[shot noise]].
Dark current is one of the main sources for noise in [[image sensor]]s such as charge-coupled devices. The pattern of different dark currents can result in a [[fixed-pattern noise]]; [[dark frame subtraction]] can remove an estimate of the mean fixed pattern, but there still remains a temporal noise, because the dark current itself has a [[shot noise]].
This dark current is the same that is studied in PN-Junction studies.


==References==
==References==
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[[Category:Electronic engineering]]
[[Category:Electronic engineering]]
[[Category:Optoelectronics]]
[[Category:Optoelectronics]]



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Latest revision as of 03:24, 31 July 2024

In physics and in electronic engineering, dark current is the relatively small electric current that flows through photosensitive devices such as a photomultiplier tube, photodiode, or charge-coupled device even when no photons enter the device; it consists of the charges generated in the detector when no outside radiation is entering the detector. It is referred to as reverse bias leakage current in non-optical devices and is present in all diodes. Physically, dark current is due to the random generation of electrons and holes within the depletion region of the device.[1]

Dark current is one of the main sources for noise in image sensors such as charge-coupled devices. The pattern of different dark currents can result in a fixed-pattern noise; dark frame subtraction can remove an estimate of the mean fixed pattern, but there still remains a temporal noise, because the dark current itself has a shot noise.

References

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  1. ^ Allam, J.; Capasso, F.; Alavi, K.; Cho, A.Y. (January 1987). "Near-single carrier-type multiplication in a multiple graded-well structure for a solid-state photomultiplier". IEEE Electron Device Letters. 8 (1): 4–6. doi:10.1109/EDL.1987.26531. ISSN 0741-3106.