1. PN Junction Diode & Zener Diode | TNPSC Radio Supervisor 2026 (Code 447) | Electronics Devices

[00:00:00]Hello friends, welcome to learners forum. So diploma.

[00:00:13]So firstunction junction diode semiconductor device. So P type semiconductor N typemicinal.

[00:00:48]So basic function and opposite direction.

[00:01:12]So diagram.

[00:01:34]So one represents P region the other represents the N type region. So basicity Continutor.

[00:02:36]So semiconductor conductor conductivity concept default important. So material better thermal stability.

[00:03:28]For example, the outermost number electron So most electron is for temperature.

[00:04:32]So outermost layer unstable.

[00:04:52]better stability.

[00:05:00]So it can withstand higher temperatures than semiconductor semiconductor extrinsic semiconductor intrinsic purest form of semiconductor impurities.

[00:05:27]electrons.

[00:05:33]So conductity.

[00:05:40]So purest form of silicurmic type of semiconductor we call it as doping. So the condenstorm.

[00:06:18]So first level of purest form of semiconductor.

[00:06:34]Purest form of semiconductority versionity increase electric properties.

[00:07:19]So type material type material.

[00:07:30]So P type semiconductor impurent examples electron.

[00:08:03]So silicon valence.

[00:08:08]So four electron and other way.

[00:08:27]for example compent [snorts] three bonds form.

[00:09:08]positive charge carrier.

[00:09:11]So majority carriers positive majority minority carriersity mainly due to holes impurities.

[00:09:43]So five outermost valence electrons which are phosphorus arsenic and antimony. So in the particular name and indicction minority.

[00:10:38]So it is mainly due to the flow of electrons.

[00:10:42]So basic compound we will have only three.

[00:11:09]So in the whole conduction so 1 2 3 4 and fiveent conduction is because of free electron.

[00:11:42]So we are adding component and majority obviousity.

[00:11:59][laughter] And it is boron, gallium or aluminium.

[00:12:11]Majority is because of electrons.

[00:12:13]Minority holes conductity because of electrons and particular phosphorus and antimony.

[00:12:28]PN junction.

[00:12:32]So type material.

[00:12:38]So way particular junction recombination creates a region free depletion region.

[00:13:31]So depletion region mobile electron IM mobile ions.

[00:14:20]So in the resistance conduction mobile conduction and wall insulating barrier.

[00:15:08]Next is barrier potential. So barrier barrier potential. So diffusion process P and because of diffusion region.

[00:15:31]So ability to move the charge. So the charge potential difference.

[00:16:11]So silicon barrier potential value is.3.

[00:16:21]Next is diffusion current. So diffusion diffusion charge lowration for exampent charge.

[00:16:56]So it moves from N to P type and it moves from P to N type minority carriers which is done by because of the influence of electric field. So depletionity for exampibrium diffusion current.

[00:17:51]So equilibrium condition just apply equibrium. condition.

[00:18:32]So point of view first thing is what is the process important potential for silicon and diffusion basic difference.

[00:19:03]So majority carrier minority and values.

[00:19:26]So basic question.

[00:19:53]Next is Zena diode. So junction diode junction diode reverse breakdown region in the particular diode function concept. So normal diode forward condition to positive to negative negative to positive and posit positive to negative.

[00:21:03]So diode heavily doped junction diode reverse breakdown for wide range of current. So heavycavy depletion.

[00:21:36]So reverse breakdown we call it as voltage V.

[00:21:48]So simple variation variation.

[00:22:05]So Z in.

[00:22:10]So this is P and junction diode and this is diode. So modes of operation we had only forward bias and bias.

[00:22:26]So forwarditive positive with negative.

[00:22:31]Soverse connected to connected Positive breakdown so that the voltage across the diode remains almost constant.

[00:23:30]in the particular we always use it for voltage regulation.

[00:23:34]Next break which occurs in heavily doped diodes. So stronger electric field below 5.6 6 and it is nondestructive if current is limited. So in the break it occurs in lightly doped. So high energy electron higher reverse voltage that's above 5.6 6 oh and it is again non deconstructive and it is again non-destructive when current is limited. So basic low breakdown and it is because of stronger electric field and due to impact ionization.

[00:25:24]So honey extract fire [clears throat] extract.

[00:25:54]lengthy process step by step.

[00:25:58]Second option process.

[00:26:13]So step by step [clears throat] it is because of breakdown so you don't get confused basist of xenode Forward region variations represent [snorts] equivalent diode.

[00:27:13]Forward bias condition it acts as a constant voltage source almost equal to the breakdown when it is connected in reverse bias condition across the loadant.

[00:27:35]Output input.

[00:27:55]We are using it for voltage regulation.

[00:28:01]input output.

[00:28:13]So either way so resistor is always connected in series with the diode We are using a resistor in series with the diode and it provides proper operating current regulation main advantage disadvantage and high current.

[00:29:33]So reverse condition.

[00:30:01]Thank you so much friends.