PN junctions and diodes

What is the phenomenon in which forward current through a PIN diode injects many carriers into the i-layer and greatly reduces its resistance?

  1. AEarly effect
  2. BConductivity modulation
  3. CHall effect
Show answer and explanation

Answer: B. Conductivity modulation

The lightly doped i-layer normally has high resistance, but under forward current, large numbers of electrons and holes are injected from the p and n layers and its resistance drops sharply. This is conductivity modulation, the mechanism that lets high-voltage diodes and IGBTs combine high breakdown voltage with low on-state voltage.

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More PN junctions and diodes questions

  1. What can be evaluated by measuring the capacitance of a reverse-biased PN junction while varying the voltage (C-V measurement)?
  2. Of the two terminals of a PN junction diode, what is the terminal on the p-type side called?
  3. What is the property of a diode that lets current flow easily in one direction but hardly at all in the other called?
  4. Which statement correctly describes the depletion layer of a PN junction in thermal equilibrium?
  5. In which direction is a voltage regulator (Zener) diode normally used in a voltage regulator circuit?