Ordinary Diode

Semiconductor Devices

Aim

To study the I-V Characteristics of an Ordinary Diode.

Apparatus

  • P-N Junction Diode
  • Battery
  • Connecting Wires
  • Resistances
  • Voltmeter
  • Ammeter

Theory

A P-N junction is formed by doping the P-type with trivalent impurities, which have excess holes, and the N-type with pentavalent impurities, which have excess electrons.

  • Forward Bias:
    A positive voltage on the P-type reduces the potential barrier, allowing current to flow.

  • Reverse Bias:
    A negative voltage on the P-type blocks current, widening the depletion region.

The junction's behavior depends on the type of impurities and the bias applied. In forward bias, there is a reduction in the potential barrier.

Cathode and Anode:

  • Anode:
    The positive terminal, connected to the P-type semiconductor.

  • Cathode:
    The negative terminal, connected to the N-type semiconductor.

  • Most diodes have a band or line marking on the cathode end, usually silver or white, distinguishing the negative side of the diode.
  • The end without the line is the anode (positive) end.

Circuits

Forward Bias:

Reverse Bias:

Graph

Result

The V-I Characteristic Graphs/Curves of P-N Junction Diodes (both in reverse and forward biases) are obtained and verified with their proven results.