How does a diode work - the PN Junction (with animation) | Intermediate Electronics

[@omarmagdi2732]

Although it's a 5 mins video but it explains a lot and what I mean by a lot doesn't just means "a lot" but it means A LOT! Thanks for the Exceptional work, and keep nourishing our minds with that great way of putting up science

[@shaheenrahman680]

1:06 1:13

[@pastalavista5628]

I like your profile pic xD

[@user-hu6ei2mh4o]

Searching for animation and till now, this is the best available video on KZbin

[@CircuitBread]

Glad you liked it

[@gameora25]

Are u from fbise?

[@CircuitBread]

We hope this video was helpful! We have a couple more videos on how diodes/PN junctions work when forward and reverse biased, we recommend you go check them out as well. We also have a wide variety of other tutorials on semiconductors, so explore our channel if you have any more questions on this topic. If helpful, we have the transcript for this video on our website here: www.circuitbread.com/tutorials/how-does-a-diode-work-part-1-the-pn-junction Take care!

[@tengisdashmunkh1787]

The question is why do course staff, who are paid for the job, fail to explain this concept as clearly and simply as this KZbin channel does! Thank you for the video!

[@lucasl4644]

init

[@nish3003]

true true on the course teachers' defense, they rly cannot explain the topics with the help of such intuitive animations shown in youtube videos but still overall I feel youtube just does a better job at teaching us lol

[@TheEsky18]

You probably gave no indication that you didn't understand the material. It's adult learning, so if you don't get the most out of what you are paying for then that's on you. Secondly, there is a bit of confirmation bias in your statement. You have obviously received several hours of face to face tuition and have tried to read your course material in your own time, yet you give 100% of the credit to this video only? Do you think you would have understood everything about diodes if you had just watched this once?

[@mmukultired3288]

@@TheEsky18 so true

[@Mohd53000]

This is the type of content that viewers seek from youtubers. Quality Content!!

[@yagmurunalan9828]

As a material and nano tech engineer it helped a lot thank you so much! This 5 min video was definitely more effective than the 2 hours lesson I took at uni

[@shanm157]

after watching many videos, this series on transistor fundamentals is the best so far. The animation is clear and the speaker makes perfect sense. Subscribed.

[@bluesapphire7548]

This is the COMPLETE explanation. Perfect. Good job!

[@claudiapratt9895]

I love this channel. Every time I feel my brain frying while studying I come here and understand it within minutes. Just excellent.

[@osmargds]

Great explanation! Thank You so much!!! Love from Brazil!

[@sorayaabdelhaleem5662]

This is so far the best explanation for PN Junction for me

[@CircuitBread]

Awesome, great to hear!

[@JustitiaVirtutumRegina]

it is simply perfect I was reading slide almost 40 mins but couldn't understand anything about concept until watch this 5 minutes video.Thank you

[@CircuitBread]

Glad it helped!

[@dr.abdelmounaimchetoui]

amazing explanation that I've ever seen before. irreproachable scientific content. Well done!

[@avadakedevra2895]

This was so helpful. I have my physics full syllabus grade 12 exam tomorrow and God semiconductors were one of the most confusing chapters...That is until I watched your videos Thank you so much. The concept is crystal clear

[@JeremyDismukes225]

thank you. this animation helped me understand what my teacher couldn't through a powerpoint slide

[@BetterMeAcademy923]

I love the way you explain and animation, it's very easy to understand

[@CloseUpFootball]

the best explanation, was looking for it for some time

[@ALittleLifeWithDriedTubers]

This series is amazing. I have been looking for a good source to learn about electronics and I've found it, without a doubt.

[@spandansaha5663]

This was by far the most intuitive explanation of band diagram of pn junction I have seen. Thanks brother. Just a minor nit pick in the animation It would have been more clearer to specify that movable charge carriers cross the pn junction and ionize the fixed carriers on the other side So the depletion region is filled with ionize fixed carriers but you showed that carriers were moving during the formation of depletion region, which I guess shouldn't happen in reality But regardless this was a fantastic video thanks

[@truptigoudar5480]

Thank you for this clear explanation. Nam professor nim kaalu kelage thurbeku.

[@omarel-ghezawi6466]

Excellent. Clear and concise. Thank you.

[@ahmedkhattab4416]

Thx sir, i would search across the internet for an easy explanation but for an 1h i could only find YOU

[@purveshsohony4119]

this video is heavily underrated

[@MPG-ub5ke]

Wow brilliant, thanks for this fantastic video, first time I actually understand how diodes actually work!

[@CircuitBread]

Awesome!

[@anjanaimesh3258]

The best video I find about diodes and pn junction. Learned a lot ❤️

[@lamtrungrau5986]

beautiful English subtitle and animation video, thank you so much teacher .From Viet Nam with love

[@Infinity-Journy]

The best explanation for pn junction diode. Hey everyone, I wanted to praise CircuitBread for creating an incredibly helpful video. The content was so informative and well-explained. I'm sure it helped many others as well. Thank you for taking the time to share your knowledge and expertise!.

[@CircuitBread]

Thanks. Glad it helped!

[@damianomartucci9814]

Finallly you helped me understanding this topic. Really thank you! Other websites make it so difficult.

[@CircuitBread]

You're welcome, I'm glad it helped!

[@zaeemshahid1511]

Its awesome.love from lahore ,pakistan.you are included in my list of best teachers.❤

[@UnKnownHerupu]

even the concept which i didnt even had an idea in one hour explanation, i understood here after 5 minutes

[@De_lione]

super helpful thank you so much!!

[@prabhatmishra5667]

Thanks. Love from India

[@sunjacky458]

Great video, explain a profound theory in a simple language

[@Pradnyneshgavali]

Such a amazing video 😍 helpful

[@an-nafiuo]

It was helpful basic electronics tutorial I even seen

[@CircuitBread]

Thanks so much for the feedback!! Check out our site CircuitBread.com for all of our tutorials plus tools, an equation library, and more! 😎

[@anissbenthami]

High quality content 👍🏼

[@zahidsumoneric]

Extra ordinary content. Thank you very much for sharing.

[@mehdikh62]

Excellent video and easy tounderstand, well done 👏

[@npetrak843]

my uni cant explain this at all, have to come to your vids to properly understand it. Thanks

[@CircuitBread]

Happy to help!

[@mdroton629]

GREAT EXPLANATION

[@सागरबड़थ्वाल]

great explanation

[@jonasmortier9056]

Hello, I'm a bit confused by the animation. when the free electrons go over to the p-site, you would think that the result would be a neutral charged atom at the N-site, but instead it becomes a positive charged hole?

[@jonasmortier9056]

I guess it is because it are mostly neutral molecules from the n-site that will lose an electron?

[@rosskappa5410]

nice video but at 1:11 electorns filling the holes shown as they stay as negative charges. As I read in a book , they neurtalize each other and some majority carriers holes and electrons are lost in this process. How negative charges exist in is because holes leave behind electrons when they diffuse throught, similar to electrons leaving out holes behind them.

[@CircuitBread]

Yep, you're exactly right - those electrons combine with the holes and while the electrons still technically exist, they're no longer important to consider as they're now tightly bound to a nucleus and there is no net charge. This is the tradeoff in trying to show a process visually that can't truly be shown visually in a realistic manner. If we'd made the hole and electron disappear, that could have been confusing in that people would have thought the electron literally disappeared, when it's really just the charges are canceling each other out. So we had to make a decision on how we thought it best to represent it. But it sounds to me like you have a great understanding of the topic, which is great!

[@rosskappa5410]

@@CircuitBread thank you for the reply and also great videos !

[@arjae1422]

Why i didn't find this video earlier U r doing great wrk I appreciate it too much

[@CircuitBread]

Thanks for your feedback, we really appreciate it!

[@jivey5123]

Finally understandable english!

[@engiiifacts730]

yes ,he is an inspiration for me ...thank you

[@GGowthamReddy-dx2un]

waiting for the bread to pop out !!

[@katlenejanemanahan6184]

this is so helpful! thank God I found it haha more videos to come :)

[@UstaadIbraahim]

Great understandable explanation❤

[@altayebofficial]

Thanks so much man

[@diegokher]

great explanation! thank you

[@mnada72]

Very informative , thank you.

[@yejieke92]

Thankkss really I have exam after 1 hour I read it in abook school I understood superficially, but I didn't really understand exactly how it happened

[@vladimirdvorak3937]

First, let me thank you for the good videos. But in this one, I wonder if it's factually correct. What I have in mind specifically is the energy diagrams at 2:30. There is not enough space to explain in detail but in a nutshell: the valence band of the p-region can be above or below of valence band of the n-region, depending on used materials. Take for example P atom with electron configuration [Ne]3s^2 3p^2 => 5 electrons with principal quantum number = 3 vs B atom (you named it as p-type impurity) with [He] 2s^2 2p^1 => 3 electrons with PQN=2. So electrons in the B valence shell have even lower energy than those in P. Ga or In atoms would work (see periodic table). Second and more importantly - when elections recombine on PN junctions the electron energy needed to escape from P atom DOES NOT change. Bands are not moving anywhere contrary to your statement in 3:41. These are still the same atoms. P atoms further in the n-region are willing to give up the extra electron same as before. These may either recombine with holes in the p-region closer to the PN junction (causing hole current) or may try to penetrate to n-region and recombine with the n-region hole. The only problem is really that there is already a barrier of earlier recombined negative ions of B/Ga/In atoms. These exert a repelling force on free electrons coming from the n-region according to Culomb's law (as you correctly explain in 2:00). In a nutshell to understand PN junction it's critical to understand 2 distinct forces - 1) Culomb's law and 2) the proclivity of electrons to fill the atom valence shell in some patterns which is key for understanding chemical bondings, the periodic table, and chemical element properties. Also, I think there is no conduction band but rather conduction space simply for all electrons with enough energy to escape the atoms. So there is always a "conduction band" overlap and an electron excited enough can always go anywhere (you only need to heat things up enough). And of course, energy comes in quantum so the conduction space is not actually continual but discrete, but it's possibly not important here. At least that's how I understand it, which also may or may not be correct. :)

[@ranjanjayarathna7267]

superb explanation

[@CircuitBread]

Thanks!

[@Timkaasjager]

Thanks for the awesome animation and explanation! Wouldn't you say that the electrons that lose energy and recombine actually make up the depletion region? In your animation, the depletion region increases but the electrons in the valence band remain outside of it. Thanks for your answer!

[@elhamahmed6892]

Great explanation, thanks for helping me to envisage it.

[@045sakshimishra7]

Great explanation....really !!!

[@vaishnavikulkarni1749]

Sir, thank you so much for making this video. It is extremely helpful and easy to understand! The textbook made me wish I would rather have my brains blown off😅😄😄😄

[@CircuitBread]

Well, I'm glad you didn't and that this helped!

[@ruzannavardapetyan]

Hi, thanks for the interesting and instructive video, but one thing I don't understand is why we can't disconnect these semiconductors from each other. Thank you!!

[@CircuitBread]

Thanks for the question! Do you mean, why we have to have the two different doping regions? If you have just a p-doped region or an n-doped region by themselves, they're just a piece of material that doesn't conduct particularly well. It's when they're put together that the magic (or science) really happens! If you're not familiar with the background on doping, I recommend starting at the beginning of our Semiconductor Basics playlist: kzbin.info/aero/PLfYdTiQCV_p7sDswtLZKK43BWOd2mTmHC

[@ruzannavardapetyan]

@@CircuitBread Thank you for the answer, I will definitely start watching. I worded my question incorrectly. I just can't understand the Seebeck effect. How does it happen?

[@kasunexe]

Thanks a lot ✅

[@taskinabdur-rahman3487]

Great video thank you

[@Professional_chemist]

Amazing channel :) thank u so much.

[@JvdeTube]

To understand the diode, you have to understand the PN junction. To understand the PN junction, you have to understand what an impurity atom, pentavalent, and trivalent is. You also have to figure out what he means by "doping". If you don't understand these things, you won't even get past the I N T R O D U C T I O N.

[@STP31]

Thank you soo much

[@kaierliang]

this is gold

[@roshanbernard5933]

Nice work,,. Btw The free electrons diffusing through the depletion region from n region rapidly lose energy... What makes them lose energy ?

[@CircuitBread]

Hi Roshan, my understanding is that the electron loses that energy in the process of overcoming the depletion region, which is acting as a barrier. In other words, it uses that energy just in the process of getting to the other side.

[@gaspardukwizagira2608]

too dope too good well done .

[@abdalwahabkhalefa7476]

والله ودي اجيك البيت اسلمك اللايك شخصيا 🤍

[@fathimasanak907]

Out of all the videos I’ve seen , this is by far the best ! Thank you so much sir 👍🏻

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[@benbadakhaoula4009]

you are the best thnx

[@BilkulSubhasmita]

Wow. This was so helpful. I wish you'd make a video on the applications of pn junction especial rectifiers Your videos just make it so much easier to understand ❤

[@CircuitBread]

We do have a couple videos on diodes (which is just a PN junction) and I've been thinking about perhaps doing a small sub-series as part of our Circuits 101 series about the applications of BJTs (which are NPN or PNP junctions).Thanks for the feedback!

[@abanoub1171]

you forgot to mention that the holes from the p type semiconductor diffuse to the N type semiconductor the same mechanism as the electrons diffuse towards the p type semiconductor. but overall video is amazing, thank you.

[@CircuitBread]

Very true, thanks for the feedback!

[@hassanelfalaky204]

Excellent

[@zoyanoor0039]

Does active region and depletion region are same in LED? IF no what is the difference please explain

[@consciousness147]

Why is the Valenzband empty? dont we need to fill lower states with electrons first ?

[@jayajohn3276]

How does the depletion layer get charge ?when n and p recombine,will there be charge

[@bhimsensatpathy4112]

Sir! As electron is negatively charged and hole is positively charged then after the electron get into hole how can there be negative charge left????? Sir please answer

[@aryanandaleebazim823]

Sir, My Second Question is why does the free electrons rapidly lose energy while falling into the holes right after crossing the p-n junction (at 3:26) (I understand WHY it should, because the acceptor energy level is lower than the valence Band obviously, I just don't know what underlying phenomenon makes the electrons lose energy) And, my 3rd Question is- similarly, what makes the overall energy level of the n region to decrease as soon as a depletion region is created? (at 3:39)

[@CircuitBread]

Your second question seems nearly philosophical when I read it. They lose energy because they tend toward the lowest energy level, just like why a marble in a bowl wants to settle in the bottom. And hitting the bottom of the bowl causes the marble to jump up, just like the insertion of energy (in terms of heat or light) causes the electrons to jump out of the valence band. Any underlying "why" below that... I don't know! Let's see if I can do an adequate job explaining the third question. Even though the overall semiconductor has the same energy, the energy has been redistributed by the movement of electrons and holes within the semiconductor. As the n region is dropping in energy, the p region is increasing in energy, so that's where you get the balancing. And it isn't decreasing as soon as the depletion region is created, it's dropping in conjunction with the depletion region being created. The two things are related. Hopefully that clarifies things!

[@aryanandaleebazim823]

Thank you so much, all your answers are really helpful. But I'm so sorry that I'm having too many questions to bother you again and again, ha ha! Anyways, so what you just said about why electrons lose energy while falling into holes (you said that it's just a natural tendency to have lowest energy) so why does that tendency come visible "after" the electron has crossed the junction? Does it mean that any valence band electron on the n side can just jump down to valence band randomly? If not, then what's making that change of energy drop ONLY after the passing of electrons? (it's fine if you can't give the accurate answer to this, I went pretty deep😅...but if you know any other resource as suggestion where I can find the best but easy explanation, that would be a great bonus favor, too) For your response to the 3rd question (energy gradient increment between n and p regions with depletion layer formation): I do want to ask that referring to one point you made in the video about why initially the energy levels of n type semiconductor is naturally a bit less than p type. There you had explained the reason in terms of effect by nuclear attractions. So my question is, if we consider the energy drop / energy jump in the respective n and p regions during the depletion layer is being formed, how can that be explained in terms of thr nuclear attractions (individually for n type and p type)?

[@CircuitBread]

@@aryanandaleebazim823 No problem! My only concern is that we're getting close to the edge of my understanding -and I'd prefer to have Dr. Campbell help (a professor and awesome person that we've used as a resource to double-check our work in microelectronics) but she's always crazy busy. So I will do my best! I think we need to expand the bowl analogy more. In reality, it's not just one bowl, it's trillions and quadrillions of bowls per square centimeter of lattice. And even though that may sound like a lot, it's absolutely tiny compared to the amount of atoms in that same area. So, at this point it becomes a statistical thing. But the more bowls there are, the more likely that an electron will find one and then fall into it to the lower energy level. Once the electrons cross through the depletion region, there are a lot more bowls, so it's statistically much more likely that the electrons will drop down in energy level at that point. If I'm understanding this question properly (which I may not be) you're trying to figure out why the n and p regions have an even greater difference in energy levels due to the nuclear forces on trivalent versus pentavalent electrons, AFTER the depletion has been formed. I think, in this case, that this is not actually the case. This change after the formation of the depletion layer is not due to the nuclear forces between the nucleus and the valence electrons but simply by the energy of the extra electrons that are moving from the n region to the p region. So, instead of the inherent differences in energy levels due to the nuclear forces between the nuclei and electrons, it's due to the physical movement of particles that have intrinsic energy. Does that make sense? I'm not sure if I could go any deeper than that without getting a degree in chemistry or physics. 😀

[@vaibhavgupta6415]

after pentavalent doping the extra electrons goes in conduction band of that semiconductor am i correct? i understood everything and clear my doubts thanks!

[@CircuitBread]

Yep! Excellent to hear. We do have some other tutorials on doping if necessary but it sounds like you're good to go!

[@RobertSirumani]

Pls put video for n type solar cell working

[@tausifahmed4885]

Why the energy of conduction band and valance band in n type semiconductor is slightly lower than those in p type conductor

[@RohithVaithiyalingam-l9r]

Sir I did not get the points 2:43 can you explain for me ?

[@eem4as]

Hi. Nice animation. Which software did you use to create it? Overall, nice video!

[@Sarrrraah]

Thanks thanks thanks thanks thanks thanks thanks thanks thanks thanks thanks thanks thanks That was very helpful 💕💕💕

[@CircuitBread]

You're welcome 😀

[@farhaneverythingof0468]

i have a question what is thee theory about reduce depletion width

[@commenter3915]

I had a question: At the pn junction where there is a layer of +ve and -ve charge opposite each other how is a region of DEPLETED charge carriers created, surely there is a concentration of charge carriers?

[@CircuitBread]

The trick here is to realize that those charges are immobile ions, not free moving charge carriers (something that is inaccurate in one of our animations, unfortunately). Does that help understanding this?

[@commenter3915]

@@CircuitBread Yes, it does, thank you, as I understand the depletion region acts as the 'barrier' in diodes.

[@ChicleenSuela]

So, when does the depletion region starts, when p and n are attach together or when voltage is applied?

[@CircuitBread]

A depletion region naturally forms as soon as they're "attached" together but then it gets wider when there is a reverse voltage. And shrinks when they're forward biased. Hope that helps!

[@ChicleenSuela]

@@CircuitBread Yeah it helps, thanks

[@dr.abdelmounaimchetoui]

can you post a video in which you explain the solar cell working principle, please.

[@CircuitBread]

Oh, that would be a good one! We have the next 6-8 months of content already roughly sketched out, but we're hoping to get Josh a little bit of help soon, if so, hopefully we'll have a bit more bandwidth and we'll try to fit this one in. Thanks for the feedback!

[@dr.abdelmounaimchetoui]

Excellent. Am waiting for your valuable courses. You're just doing great !

[@aycaakbas629]

which app did you use for these videos?

[@CircuitBread]

Hi Ayca! Our videos guys use the Adobe Suite for video editing. I think it's Premiere for the video editing itself and Aftereffects for the animations.

[@amadoucisse2692]

can you explain reverse recovery some time

[@MohamedKhaled-xe8yp]

can we refer to this type of attraction (electrostatic) between positive charges and negative charges (ions) as an ionic bond attraction or ionic bond is different from this case?

[@CircuitBread]

No, they're not an ionic bond, and it's not really an attraction, more just varying energy levels and things naturally wanting to drop energy levels by falling back into a hole. Hopefully that helps!

[@utkarshjaiswal9441]

Hello sir I'm big fan 🙏

[@CircuitBread]

Thanks Utkarsh!

[@AffinityKRC]

The video would have been better if you had used simpler words. I had to look up valence, trivalent, and conduction band

[@nahianislamashikashik6466]

2:28 Why n-type bands are lower than the p-type bands?

[@justinsantos5751]

I think it's because the opposite is true for pentavalent atoms compared to trivalent atoms. Pentavalent atoms exert much more force on the outermost electrons, causing the orbits of the outermost electrons to be much lower and nearer to the source. Hence the bands in n type are located at a lower energy level compared to the bands in p type.

[@miriamjaymes]

@@justinsantos5751 I think so, too! my professor said that "The bigger, pentavalent atoms are "attracting" their outermost electrons more, so their energies are lower, meaning, further from the 0, i.e. the vacuum level."

[@oraange]

I have one question , does the electron only move to p region ? because I heard and read that holes move to n region , i'm a bit confused.

[@CircuitBread]

Electrons and holes move around in both regions. The only difference is that there are more holes in the p-region and more electrons in the n-region. Things like to equalize, so as long as there aren't any external forces, electrons will diffuse into areas with more holes and holes will diffuse into areas with more electrons - this is diffusion current. Things are complicated by the fact that there are additional forces, both active and inherent in PN junctions, that oppose this motion.

[@samad4942]

Why when the depletion area expands, the energy level of conduction and valence decreases in n region, "energy level or energy band of solid should be constant"

[@xd-kt2nl]

Thank you thats help alot

[@AnshulSharma1997]

Can you kindly explain the reason why p side energy levels are made higher and in n-side they are made lower. Also why in the state of equilibrium holes and electron Fermi level align at same position in order to achieve equilibrium. Also as holes and electron which flow are actually in bond with the atom, so hows does when they are in contact, what provides them energy that electrons move and fill the vacant charges in p side leaving a hole or vacant side in n side.. In many texts i have seen (but still confused) that they say, electron are near conduction band so as electron moves they actually decreases the amount of Fermi level in n side due to vacancy and increases the Fermi level o p side... but the logic that Fermi level will align finally for both p and n side, i am unsatisfied with it...Some says as depletion region is formed so why further movement of electron and holes do not occur that electron may go to conduction band of p region. Sorry a bit long query and may be dumb question, but please do clarify this and hope you reply to me. Also you said that electron coming from n type to p type during diffusion will fall back to valance band of p region. How can you represent this situation in a pn semiconductor. is it that the electron recombine with the immobile ion created in p region or what.

[@gotobawa]

Depletion layer has No charge then why u asign it by + & - charge