What is the purpose of depletion region?
The word depletion in English refers to the decrease in the quantity of something. Similarly, in semiconductors, the depletion region is the layer where the flow of charges decreases. This region acts as the barrier that opposes the flow of electrons from the n-side to the p-side of the semiconductor diode.
In which region is Zener diode used?
The Zener diode will be operated in the reverse breakdown region so that the voltage will remain constant. Therefore option 3 is correct. In that region, the voltage will be equal to the breakdown voltage and this will make the Zener diode work as a voltage regulator.
What is the importance of the depletion region in a PN junction diode?
In absence of a depletion region, all the majority charge carriers from the n-region (i.e., electron) will get transferred to the p-region and will get combined with the holes present in that region. This will result in the decreased efficiency of the p-n junction.
What is the significance of the depletion region in a semiconductor diode?
A region in a semiconductor device, usually at the juncture of P-type and N-type materials, in which there is neither an excess of electrons nor of holes. Large depletion regions inhibit current flow.
Which region is heavily doped in a Zener diode?
Zener diode is fabricated by heavily doping both p- and n-sides of the junction so breakdown occurs at a voltage of about 5 V in reverse bias. A Zener diode is fabricated by heavily doping both p and n-sides of the junction.
What is the significance of Zener diode?
A Zener diode permits Zener current, Iz, to flow when the voltage is above the specified Zener voltage. Thus, a Zener diode can be used for voltage detection by sensing Zener current with some other device.
Why are zener diodes used for voltage regulation?
The Zener diode is often in use as a voltage regulator, primarily because the voltage drop across the diode is constant. Furthermore, the supply voltage must exceed the Zener voltage for the circuit to operate. Thereby, any electronic component connected in parallel with these diodes will have the same applied voltage.
What is the importance of depletion layer?
The depletion layer at the interface between a compact semiconductor and a liquid medium plays an important role in light-induced charge separation. The local electrostatic field present in the space charge layer serves to separate the electron–hole pairs generated by illumination of the semiconductor.
What are the features of depletion region?
Answer: A depletion region is a natural feature of doping a semiconductor n-type and right next to it p-type. At the p-n junction (the border of the two types), the mobile electrons in the n-type (this is due to the excess electron provided by the n-dopant) diffuse across the junction, into the p-type area.
Why depletion region is small in Zener diode?
The p-n junction of the Zener diode is heavily doped to get a narrow depletion region. The narrow depletion region allows the ions to easily gain energy from the external source. In the reverse bias, the junction potential of the Zener diode is increased. It results in an increased current through the Zener diode.
Why is depletion layer thin in Zener diode?
At junction(initially), carriers diffuse from their higher concentration to lower concentration and left behind ions, since the ions formed are more per unit length( since their concentration is high) the depletion layer is very thin.
Why Zener diode is only used in reverse bias?
It acts as a normal diode in forwarding bias. When the Zener diode is reverse biased the junction potential increases. As the breakdown voltage is high this will provide high voltage handling capacity. As the reverse voltage is increased, the reverse current increases drastically at a certain reverse voltage.
Why is Zener diode used as a voltage regulator in reverse bias?
When the Zener diode is given reverse bias feedback, there is a small leakage current until it attains the breakdown voltage or a constant voltage. At this point, the current begins flowing seamlessly without any change in voltage. Therefore, the constant voltage helps Zener Diode as Voltage Regulator.
Why is the depletion region of Zener diode very thin?
The depletion region of the Zener diode is very thin because of the impurities. The heavily doping material increases the intensity of the electric field across the depletion region of the Zener diode even for the small reverse voltage.
What are the common applications of Zener diode?
The Zener diode has the following common applications: Voltage reference: When a load circuit has to be supplied with a fixed voltage, it can be connected in parallel to a Zener diode of the same Zener voltage. In this way, the voltage across the load device/network will appear the same as the Zener voltage, but never higher than that.
What is the depletion region of a diode?
The diode consists of a very thin depletion region as it is made up of heavily doped semiconductor material. In a Zener diode, high-level impurities are added to the semiconductor material to make it more conductive.
What does the graph of Zener diode breakdown represent?
The graph represents that the Zener diode has resistance. Further, it is shown that the graph of Zener breakdown is not exactly vertical. The voltage across the Zener diode is represented by the equation given by. The major use of Zener diode is in industrial and commercial applications.