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What is depletion region in a semiconductor diode?
Depletion region or depletion layer is a region in a P-N junction diode where no mobile charge carriers are present. Depletion layer acts like a barrier that opposes the flow of electrons from n-side and holes from p-side.
What is depletion layer and how it is formed?
The depletion region is caused by the diffusion of charges. The holes and the electrons diffusing towards each other combine near the junction. In doing so positive and negative ions are formed. The pair of positive and negative ions at the junction forms the dipole.
Why an electric field is produced in a depletion region of a pn junction?
Light travels in packets of energy called photons. The generation of electric current happens inside the depletion zone of the PN junction. The hole created by the dislodged electron is attracted to the negative charge of N-type material and migrates to the back electrical contact.
What is application of PN junction diode?
The junction which is the p-n junction diode can be used as a photodiode, the diode which is sensitive to the light when the configuration of the diode is reverse-biased. It can be used as a solar cell. When the diode is forward-biased then it can be used in LED lighting applications.
How is a depletion region created in a JFET?
A depletion region is created in the channel that makes the channel narrower, increasing the channel resistance between the source and drain, and the current flow becomes less. Similarly, in the P-channel JFET, the channel is doped with acceptor impurities, making it a P-type semiconductor.
What is the name of the depletion region in a channel?
This causes a depletion region in the channel and prevents the flow of current. Thus as the flow of current is affected by the formation of the depletion region, it is called depletion MOSFET. 2.
How is a depletion mode MOSFET similar to an open switch?
The depletion-mode MOSFET is similar to that of an open switch. In this mode, the Gate to Source voltage (VGS) is applied to switch OFF the device. When the gate voltage is negative, positive charges get accumulated in the channel. This causes a depletion region in the channel and prevents the flow of current.
Why is the depletion region called the conducting region?
The depletion region is so named because it is formed from a conducting region by removal of all free charge carriers, leaving none to carry a current. Understanding the depletion region is key to explaining modern semiconductor electronics: diodes, bipolar junction transistors, field-effect transistors,…