What is Dark Resistance of a Photodiode?

1 Answer
Can you answer this question?

- GoPhotonics

Oct 25, 2023

The dark resistance of a photodiode, often referred to as the dark current or dark current resistance, is a measure of the photodiode's resistance to the flow of electrical current when no light is incident upon it. In other words, it quantifies the leakage current that flows through the photodiode in the absence of light or photons.

Dark resistance is typically expressed in ohms (Ω) and represents the resistance of the photodiode's semiconductor material in the absence of an applied voltage or light stimulation. It is of the order of picoamperes to nanoamperes.

When no light is present, electrons and holes generated by thermal energy can still move within the semiconductor material, resulting in a small, typically microampere-level, reverse-biased current. This dark current can be attributed to thermally generated carriers (electrons and holes) in the absence of photon excitation.