V-I characteristics of P-N junction diode

Hello friends we are back once again with a new post. In the last post we have given an idea about 

P-N junction diode. Today we are here to discuss about the V-I characteristics of P-N junction diode.

V-I characteristics of P-N junction diode:

In earlier we  discussed about  P-N junction diode and types of biasing. In this post we will  study the V-I characteristics. For this we have to plot  a graph for applying voltage and current.

Fig-1: V-I characteristics of P-N junction diode.

In the above figure voltage is taken on X-axis and current is on Y-axis. Here Vf indicates the forward voltage and Vr indicates the reverse voltage and If indicates forward current and Ir indicates reverse current. Knee voltage is the forward voltage at which the current through the P-N junction increases rapidly and breakdown voltage is the reverse voltage at which the current through the P-N junction slowly increases due to minority carriers. 

For forward bias:

As forward voltage is increased, the depletion layer decreases,beyond a threshold voltage the current starts conducting and that voltage is know as "cut in voltage".

Before cut in voltage the curve is non linear. After applying voltage more than cut in voltage the current starts flowing due to depletion layer decreases and the curve after cut in voltage is linear.

For reverse bias:

In fig-1 as the reverse bias is increased the width of depletion layer increase, beyond a breakdown voltage small current flows due to minority carriers flows through the diode.If reverse voltage is further increased the kinetic energy of electrons becomes so high. The knockout of electrons from semiconductor occurs at this case breakdown of junction is occur.

This is all about the V-I characteristics of P-N junction diode.Next we will discuss a new topic in this chapter. Thanks for visiting us stay tuned for more updates  please follow and share to the maximum extent for a better people to stay in..