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A simple model of a transistor/LED/photodiode

  1. May 21, 2009 #1
    any objections to using this simplified model to explain current amplification to beginners?


    "A simple model with many of the properties of a transistor, especially a phototransistor, is a forward biased LED (emitter–base junction) and a reverse biased photodiode (base–collector junction) sharing an anode (base) in a single package so that 99% (1-1/βF) of the photons emitted by the LED are absorbed by the photodiode. Each electron-hole recombination in the LED produces one photon and each photon absorbed by the photodiode produces one electron-hole pair therefore each electron injected into the base, and therefore the LED, would result in 100 (βF) electrons at the collector"


    http://en.wikipedia.org/wiki/Talk:B...nsistor_consisting_of_an_LED_and_a_photodiode
    this explanation was directly below the section starting with:
    "An NPN transistor can be considered as two diodes with a shared anode region"

    for reference:
    http://en.wikipedia.org/wiki/Geometric_series
     
    Last edited: May 21, 2009
  2. jcsd
  3. Aug 20, 2010 #2
    apparently such a device is called a "photon coupled transistor"
     
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