The PN junction | Class 12 (India) | Physics | Khan Academy

[@naomiemredha866]

OH MY GOODNESS, THIS WAS INSANELY GOOD. BEST PN JUNCTION VIDEO ON THE INTERNET

[@360wheelz5]

Indeed. After recombination, the immobile charged ions are left behind which set up the barrier potential. I couldn't understand what it was that set the barrier but now I know!

[@Mahesh_Shenoy]

You know, while I was making the video, this was the reaction I hoped for. Thanks for making it true!

[@siddharthamondal4346]

@@Mahesh_Shenoy Awesome video sir.

[@blueblood-_-]

Exactly This is has to be the best video . Explained so nicely , even the smallest doubt was cleared. Amazing

[@suryanshkhatri7929]

Agreed, 4 years after it was made, and 2 years after this comment was written, it's still the best video

[@jessiondiwangan2591]

I spent my whole year looking for this kind of teaching, finally i found ya

[@singshokeen6514]

Agree

[@avikbrahma4691]

Same for me too

[@arthureaton8]

Goodness! I've been an electronic engineer for more years than I care to admit. On occasion, I still like to review the fundamentals to keep my knowledge fresh, so I've heard the P-N junction story many many times. But I have to say, this was the best explanation I've ever come across, and even after all these years practising engineering, this little video has greatly improved my understanding of this very fundamental concept.

[@s.3421]

Guys I bet uh, u won't get a better video than this in the whole of the utube!! I wasted a lot of time, searching for a video where I could understand p n junction clearly... And then I found these videos where I understood it finally!!! Tqsm🙏🏻🙏🏻👏🏻👌🏻🥳🥳

[@esphilee]

I have watched no less than 6 videos. This video is one that makes sense. The rest are like my school teachers, they just brush things under the carpet and call it a day. Well done.

[@dhurbarajpuree2992]

3 times I rewatched.... It's a gem video.

[@ਝਲਕ]

I m in love wd this topic now , no crammed concept , just pure physics and physics . This is insane 😍

[@anonymous20060]

And little bit of chemistry 😊

[@Kyle_da_athlete]

Literally the only video on this topic that got me to understand this can't thank you enough

[@Angel-ud9jm]

Awesome way of teaching.its the best video I have seen in KZbin that explains about pn junctions,diodes..... I really appreciate you👏👏👏

[@freeverse4210]

Best thing Khan Academy (especially Khan academy india) did to me is that they developed intrest of physics and now I have such a fond to listen these lectures it gives my mind a massaging effect

[@shaikrafiq9498]

Sir u are incredibly smart .... am feeling too happy and a sought of courage developed in me that i could achieve any thing by khan academy🙏🙏👌

[@nareshsharma2003]

All your videos explained with such clarity, its the best way i gained knowledge... Loved it! Please keep making them ❤️

[@carolinerozario9702]

You're the best sir!!! Just loved the explanation! You deserve more n more subscribers... on the other hand, unacademy n etc just advertise their platforms! But Khan Academy is so service oriented! Loved it! Thanks so much!!

[@Parapresdokian]

2:09 I always love humour mixed with spontaneity. Mahesh should start his own patreon. I sooo badly don't want this man to quit his job for monetory reasons.

[@kokilamani4084]

Sir, I searched this type of teaching from many channels.... and finally u gave....osm teaching sir...... lucky to get this video....tq so much sir...u did really an immense work....keep going.....sir....

[@brothercavil491]

At 7:17, why isn't the minority carrier electron from the P side not repelled by the negatively-charged Boron. I get that it's attracted to the positively charged Phosphorus, but it has to get past the Boron first...

[@bxbybxnny5640]

I think its just because its energetic enough

[@bhaskarkothala5169]

No Marvel no Dc. These videos introduces another universe.

[@dakshinaak.s.5638]

BEST VIDEO AVAILABLE ON INTERNET FOR THE EXPLANATION OF MOTION OF CHARGES IN PN JUNCTION

[@riturajborah382]

Excellent explanation! Thanks a lot for such free amazing content! Regarding the PN junction, we could also look at it from the perspective of neutrality. Overall, the p-side and the n-side, both are neutral and they want to remain neutral. At the PN junction, naturally, the nearby electrons and holes will recombine, but only to an extent where the tendency to remain neutral will pull the charges from going further. For example, on the p side, when some holes are neutralized by the electrons from the n side, there will already be some net extra -ve charges on the p side. These charges will resist further charge migration towards the p side. The same for the n- side.

[@whomptilizes]

Absolutely amazing. You're the best!

[@bns-xt6wf]

4:18 That would be extremely so bad... We worked so hard to get to this point? Right? That was so good

[@catharperfect7036]

Took me a long time to find someone to explain this clearly.

[@rachitmehta7738]

This is just tooooooooo gooooddd . I was almost crying because this was hard to get, but this was amazing !!! THANK YOU

[@lakshmishajahan8391]

This was very helpful! Thanks allot. I finally understand it!

[@arunavomondal9750]

The best teaching I have ever found... 🙂🙂🙂

[@LeviAckerman-kk2ie]

Super useful... Better if u explained how electron and hole destroyed each other 🤔

[@wassupdee13]

Love his explanation and kindness to answer some of the key questions posted by others. They are very helpful. I appreciate it so much!

[@prachisharma1545]

That was so conceptual ❤

[@ramaswamy499]

If we see this video we can easily understand p-n junction best video thank you

[@260eeeprasuna2]

You give a clear clarity on the concept.... Great 🤝🏻

[@ramanjitkaur3124]

Justttt wowww❤

[@armyarmyyeah.0727]

Thank you..I needed this badly

[@sadiaafrin4208]

The best lec I've ever seen on this topic😍😍😍

[@KrrishNandrajog07]

Feel aagayaa 🔥

[@harshitasharma4820]

i hour i spend on utube so that i can understAND THIS TOPIC BUT then i came to this video andd hasshhhhhhhhh.... i am able to understand everything thankuuu sooo much i was soo confused before but now i understand it very well

[@parthparmar6901]

Best pn junction explanation video

[@user-zq4zt1qc3e]

what an explanation thank you very much

[@laibakhan3905]

Asslamalikum Sir! Why minority charge carriers don't diffuse with opposite charge to become neutral, like why holes in n region attracted by electrons to form neutral atoms?

[@aloomaloo1427]

Because opposite charges attract each other .

[@madivalappamakond4060]

Thank you sir for giving this beautiful lecture which I never understood when my teacher teach me

[@osamazahid715]

you did such a brilliant work!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[@aragornsonofarathorn3461]

thank you so much. I cant possibly express how grateful me and my friend are. thank you! :)

[@ShawnDypxz]

At 5:48, I know that holes can't diffuse; it's the valence electrons which are moving. Now, my confusion is - are those valence electrons of the p-type or the n-type? If the free electrons can't make it to the p side due to the repulsion ( but there are some energetic ones), I don't think valence electrons of the n-type can contribute to the hole current because they have very much less energy level than the free ones. And what does it mean by energetic holes? Could you clarify this, please?

[@mobrienmagpie]

I have a similar issue with this, also it describes holes as being attracted to the negative ions, I don't think this is correct.

[@sereneantoleslie1754]

@Mark O’Brien Yes how can holes be attracted to negative charge? Bcuz Neutral bodies cannot be attracted to charged bodies. And holes are actually neutral..they are ONLY CONSIDERED as positively charged particle. Am I right?

[@abdurrahmanfaiz6230]

I have a question. Why the electrons can't attract the holes but the negative ions in the depletion regional can attract the holes to the p side?

[@kapilraj3129]

The best part is that it doesn't have ads

[@jaredmusci5403]

Extremely helpful explanation! Watched so many videos and failed to understand the formation of the depletion layer, but this seemed to make sense so thank you. QUESTION: why can't the minority charge carriers from either side recombine with the majority charge carriers from that same side? In other words, why can't the minority electrons on the p-side diffuse into the majority holes on the p-side (or vice versa for n-side)? From a gas diffusion perspective, this makes sense since they stem from the same gas, but in reality electrons and holes are not actually gases. I assume it has something to do with the energy gap between the valence and conduction bands but am still a bit confused. If you see this, thank you.

[@purbasadas6819]

Bestest video..I hav ever seen.. thank you very much...✌️✌️

[@NiharikaAChirayil]

Thanks for the video it helped!

[@shivamprakash6412]

Once I heard that its not teaching but a students mind which make him topper but after watching this I realised that its teaching which makes a student mind topper.👍🏼👍🏼👍🏼

[@chaeonxxx6404]

Topper has another meaning. But learner

[@chaeonxxx6404]

It’s not about making a student topper man it’s about information and knowledge to apply in modern physics better than these technologies

[@fazeelmohammad8236]

Which app u used to teach pls tell

[@bholarajwar7022]

Amazing.....

[@Priyanshu_Kumar_Pandey]

Thanku so much sir

[@anitajanu9638]

Realistic and enthusiastic explanation 😊😊

[@tejuniversal5872]

Super nice excellent ❤❤❤❤❤❤❤❤❤

[@Hino_55]

CLEAREST EXPLANATION BY FAR! Thanks Sir Mahesh! :)

[@inanis6707]

I thought i knew this concept because I could spew out big words, but thank you so much. Marks do not mean you understood the concept

[@ahmadeldesokey9844]

Beautiful mind

[@boltez6507]

Wait wont the minority charges(free electrons) in P tupe fill up the holes??

[@pranavkrizz1553]

I need to know how those animations were made🤯

[@s.h.1991]

You’re a life saver i swear

[@anishatadkod1778]

I am speechless

[@OuranosGod]

Thank you man! I finally got it! ❤️

[@mariaacosta6771]

you are sooooo good!!

[@techsinc]

Holes can attract electrons via Coulomb interaction. Otherwise, you would not have the built in field at the PN junction.

[@khamisfarid3804]

Anyone knows how those videos were made ?

[@mohdkashif263]

Best video on youTube thnx so much

[@GymMeducation]

How can holes be attracted by -ve charge because actually they are nothing but vacant spaces? And can we say that when free electron goes from P to N it creates a hole in P?

[@KhanAcademyIndiaEnglish]

You are right holes and electrons don't attract each other. They are diffusing into each other just like how gases would tend to mix (without any attractive force). For your second question, I used to think the same way. But no. The moving electrons are the ones in the Conduction band. A hole moves when an electron in a jam packed Valency band shifts to a neighboring vacant space.

[@ShawnDypxz]

@@KhanAcademyIndiaEnglish So, when conduction electrons, in the course of diffusion, fall into the hole (I mean - occupies vacant space) energy is released in the form of photons, right?

[@electronicswithmadhan1052]

@@ShawnDypxz Yes absolutely correct that is the basic principle for the working of LED. That photons may be of light or heat that depends upon the band gap.

[@sagark.p2876]

8:00 awesome

[@guuguu7559]

This is insanely underrated

[@SuperSaltyFries]

Great video, thank you very much.

[@madhum8270]

Oh my god!!!! This is so amazing.😃

[@divyansh_2505]

jimin in pfp kekekeke fellow army

[@madhum8270]

@@divyansh_2505 and you taehyung 😩💜

[@AJ._7]

💀​@@madhum8270

[@mpscscience7609]

Awesome explanation......

[@vishank7]

Hello sir, I dont understand how the movement of minority charge carriers is aided. Let's say weve got an electron in the Pside, while going towards N(left to right), wont it face a wall of negatively charged atoms in the depletion region first? How doesnt that stop hinder the election's movement? Thank you already!

[@ajithettiarachi3650]

They are actually neutral due to their associated electrins

[@AarshWankar]

It doesn't, as an electron on the p side faces attaraction from the positive layer on the n side and repulsion from the negative layer of the p side, both of which are equal in magnitude. So the net force on an electron on the p side is zero. So it can randomly pass into the depletion layer after which it will get accelerated towards the n side due to repulsion from the left and attraction from the right.

[@richardknipe2733]

Excellent teacher!

[@gekinmepan]

At 7:08, I don't understand why the minority charge carrier (electron) doesn't recombine (is destroyed) as it is surrounded by holes. In the beginning of the video you explain that the depletion region is formed because electrons and holes recombine there. So why aren't the minority charge carriers recombining?

[@akshatagrawal5908]

Hey to answer this you can Study the Electron Band theory and The covalent bond theory Long story short, The holes are present in the Valence shell(n th) of Semiconductor and Free electrons are in the Shell above the Valence shell(n+1 th). Thus majority and minority charge carriers in the same Semiconductor cannot combine Also remember holes moving are just electrons of the covalent bond moving in the opposite direction

[@gekinmepan]

@@akshatagrawal5908 Thanks for answering. However, I don't fully understand you. Saying that (n th) holes and (nth +1) electrons cannot recombine is strange to me. I can understand that this may happen at a different timescale, and therefore it has time to drift to the other side, but the recombination is possible.

[@tashithadilshan3738]

Super explonation

[@purushothaman5484]

One little flaw in what he said that is he said holes are energetic what he meant was the electrons are energetic bcoz the electrons are particles and they have energy not the holes

[@rayaankhan7461]

Hey, great video...also u sound like kumail nanjiani :p

[@rijuwanahaque8054]

Thank you broh

[@abhishekahirvar7783]

here is some high quality study material

[@vigneshreddyjulakanti7583]

The BEST

[@ShawnDypxz]

Can someone answer this? @ 7:25 If free electrons from N-side can't make it to P side due to repulsion from negatively charged ions in the P side, how can minority electrons even move forward toward N side? Shouldn't the negatively charged ions repel the electrons from P side too? I know that they can be repelled forward but every time they move forward, there are always negatively charge on their way.

[@KhanAcademyIndiaEnglish]

You are right, guess could have used a better model. So in reality a minority carrier (like electrons in P type) don't wander around (as explained in the video). Since they have a high chance of combining with some majority carrier (like holes in P side), they would move very little before they recombine. However due to thermal generation another minority (and a majority) carrier will pop up somewhere randomly. So we can imagine these minority carriers popping up randomly, living for a short time and then disappearing. Since they pop up randomly. Sometimes they will pop up in the depletion region. This is when they get swept across due to the attraction (causing drift current)

[@ShawnDypxz]

@@KhanAcademyIndiaEnglish Thank you so much.

[@keerthanasingaravelan7209]

@@ShawnDypxz give khan academy $50.....

[@ShawnDypxz]

@@keerthanasingaravelan7209 I donate sometimes.

[@rimjhimshukla365]

i have a doubt on the same lines. First of all, i didnt get how they can randomly pop up in the depletion region out of nowhere because there shouldnt be as much thermal agitation in the depletion region as in the other regions. Second, even if they do, there is a 50% probability that they pop up in the p side or in the n side, i,e, there is only a .5 probability of getting swept across the depletion region.

[@magicalwings1065]

Sir I have a doubt .How can a hole move like electron? Holes are not actually particles,aren't they? They are just vacancy of electron. Then how can they move?

[@inanis6707]

I believe its actually the moving of electrons from the N type towards the P type. We say holes are moving as well for qualitative purposes but in reality it will and always will be electrons. There is no positivity in this world only electrons.

[@jeanxza5395]

I don't understand why the rogue holes/free electrons don't just combine with their counterparts. Aren't holes just the absence of electrons in the covalent bond? So why would a rogue free electron in the sea of holes not immediately go and fill any hole it finds?

[@abhinav1299]

Ahh so finnally my doubts are clear

[@niravsavla9993]

Just asking so at equilibrium n-side develops a -ve charge and vice versa for p-side?

[@KhanAcademyIndiaEnglish]

Yes. As you will see in the future videos, this is the reason there is potential difference generated.

[@ToHereCan]

During the movement of minority charge carriers, how can holes be attracted to the boron anions because I thought it was previously said that they are not actually positively charged particles themselves?

[@hannahsahasra8917]

The minority charge carriers here are not in a way attracted to the boron anions , it's the electric produced from n to p Makin them move and this is why the the minorty charge carriers in n type ie holes are sucked well not technically 😂 but yeah they r sucked into the n type and same goes with minority charge carriers in n type

[@abdulwajeed3479]

Damnnn good explaination!!!!

[@shaikrafik6300]

Amazing

[@jahanvidixit9497]

U rock🔥🔥👏👏👍👍💥💥

[@bajikeisuke8358]

what does it meant by destroying each other

[@bxbybxnny5640]

7:40 why didn't they recombine?

[@vidhyapriya4722]

thank you soo much !! gr8 work

[@Aradhikamahajan9892]

Why acceptor ions are negatively charged before diffusion

[@manmohanbisht69]

U shoud have mentioned drift word. Along with diffusion

[@xiaohanjiang4960]

Why do holes and positive charge repel?

[@ourtamilnadu9011]

Sir,how diffusion causes charged zone in junction

[@fromexoplanet21]

Wow👏💖

[@harshavardhanhajeri1753]

Can we do hcv after this?

[@niranjan7457]

Sir, at 07:18 Doesn't that lonely electron get repelled by those negative Boron atoms? As the lonely electron has to cross those negative Boron atoms before reaching those positive Phosphorous atoms?

[@electronicdevices6496]

Awesome