Photodiode

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Photodiodes

A photodiode is a light sensitive semiconductor. It is a type of photodetector capable of changing (or converting) light into either current or voltage, depending upon its connections.[1] It is a diode and wired with reverse biasing so that when in the dark, only a small amount of current, known as dark current, will flow. When in the light, a current known as photocurrent flows through the diode.

Photodiodes may contain optical filters, built-in lenses, and may have large or small surface areas. Photodiodes usually have a slower response time as its surface area increases. The common, traditional solar cell used to generate electric solar power is a large area photodiode. Photodiodes and phototransistors look the same physically but have different functions.[2]

It is based on a reversed bias circuit.

References[change | change source]

  1. International Union of Pure and Applied Chemistry. "Photodiode". Compendium of Chemical Terminology Internet edition.
  2. Cathleen Shamieh; Gordon McComb, Electronics For Dummies (Hoboken, NJ: Wiley Pub., 2009), p. 337