Explain with the help of a diagram, how depletion region and potential barrier are formed in a junction diode. If a small voltage is applied to a p-n junction diode how will the barrier potential be affected when it is (i) forward biased and (ii) reverse biased?
Assertion: In forward biasing current starts when minimum voltage of battery becomes equal to knee voltage Reason: Upto knee voltage barrier potential of diode prevents the motion of holes and electrons.
In p-n junction diode, near junction holes combine with electrons, and impurity ions form a barrier potential which opposes the recombination of electron-hole pairs. Value of barriers potential for Si is 0.7 volt and for Ge is 0.3 V. thus charge density at the junction becomes zero and an electric field is produced near junction. this region is called depletion layer. Thickness of depletion layer is of the order of 10^(-6) meter. in forward bias p terminal is connected with the positive terminal of cell and n is connected with negative terminal of cell and n is connected with negative terminal of cell. as forward voltage is increased, current increases exponentially. As forward voltage is increased barrier potential in p-n junction diode is
Assertion Forward bias reduces the barrier pitential Reason : potential barrier always oppsoes the applied potential
Explain the formation of depletion layer and potential barrier in p-n junction. Draw the circuit diagram of a half wave rectifier and explain its working.
What is p-n junction? How is a p-n junction made? How potential barrier is caused in it.
