Difference between pn junction diode in forward bias and reverse bias
The diode is an electronic component which allows current to flow in only one direction. The diode is formed by pn junction in which n side have charge carriers electrons and p side has positive charge particle holes. There is an depletion layer between the p side and n side. This depletion layer stops the further flow of electrons. When we apply positive terminal to p side and negative terminal to n side then the diode goes in forward bias so electrons can easily move across the junction to fill the holes, and a current flows through the diode. When we apply positive terminal to n side and negative terminal to p side then the diode goes in reverse biased and the depletion region width increase and electrons cannot easily move across. The difference between them is as follows
pn junction diode in forward bias | pn junction diode in reverse bias |
1) The positive terminal of the external voltage source is connected to p side and negative terminal is connected to n side.
2) The flow of current take place in the forward bias condition. 3) The width of the depletion region is less in forward bias condition. 4) As the depletion layer is less, the resistance is low. 5) The forward current is large in the forward bias. 6) The barrier potential is reduced in the forward bias. 7) The anode voltage is greater than the cathode voltage in forward bias. 8) pn junction diode in forward bias oprates as a conductor.
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1) The positive terminal of the external voltage source is connected to n side and negative terminal is connected to p side.
2) There will be no flow of current in reverse bias condition. 3) The width of the depletion region is greater in the reverse bias condition. 4) As the depletion layer is large, the resistance is high. 5) The forward current is short in reverse bias. 6) The barrier potential increases in reverse bias. 7) The cathode voltage is greater than the anode voltage in forward bias. 8) pn junction diode in reverse bias oprates as a insulator. |