V-I characteristics of P-N junction diode

P-N junction diode is made up of P-type silicon and N-type silicon semiconductor materials. This article gives the characteristics of the P-N junction diode to know more details about the P-N junction diode.
  • When the anode is positive with respect to the cathode, the diode is to be forward biased. From Vs = 0 to cut in voltage, the forward diode current is very small. 
  • Cut in voltage is also known as threshold voltage or turn on voltage.
  • For a lower power diode, current in the forward direction increases first exponentially with voltage and then becomes almost linear.
  • When the cathode is positive with respect to the anode, the diode is said to be reverse biased.
  • In the reverse biased condition, a small reverse current called leakage current.
  • The leakage current is almost independent of the magnitude of reverse voltage until this voltage reaches breakdown voltage.
  • At this reverse breakdown, the voltage remains almost constant but reverse current becomes quite high limited only by the external circuit resistance.
  • A large reverse breakdown voltage, associated with high reverse current, so power is lost and maybe diode is destroyed.
  • This shows that the reverse breakdown of a power diode must be avoided by operating it below the specific peak reverse repetitive voltage.