Photodiodes - (working & why it's reverse biased) | Semiconductors | Physics | Khan Academy

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  • เผยแพร่เมื่อ 28 พ.ค. 2024
  • Let's explore the working of a photodiode - a PN junction that converts light into electricity - its working, its applications, and why it's reverse biased.
    Khan Academy is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We offer quizzes, questions, instructional videos, and articles on a range of academic subjects, including math, biology, chemistry, physics, history, economics, finance, grammar, preschool learning, and more. We provide teachers with tools and data so they can help their students develop the skills, habits, and mindsets for success in school and beyond. Khan Academy has been translated into dozens of languages, and 15 million people around the globe learn on Khan Academy every month. As a 501(c)(3) nonprofit organization, we would love your help!
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    Created by Mahesh Shenoy

ความคิดเห็น • 123

  • @AJ-td1sb
    @AJ-td1sb 2 ปีที่แล้ว +32

    I'm currently doing an electrical engineering course. I mute the lecturer to listen to your explanation instead. Terrible isn't it. But thanks very much for putting these up.

  • @personanongrata8690
    @personanongrata8690 3 ปีที่แล้ว +93

    The content is amazing and your accent makes it 10 times better! This is the very first time I am finding physics interesting! Thanks

    • @Ivan0001
      @Ivan0001 2 ปีที่แล้ว

      *electronics

    • @adeebahmed1067
      @adeebahmed1067 ปีที่แล้ว +3

      @@Ivan0001 its a part of a chapter in physics genius!

  • @andreadanniballe5013
    @andreadanniballe5013 3 ปีที่แล้ว +51

    Couldn't find a better explanation than this one, simply brilliant! God bless you and thank you so much!

  • @divyamkumarpandey7749
    @divyamkumarpandey7749 3 ปีที่แล้ว +20

    Please add this video to the semiconductors playlist

  • @ShaunFMichael
    @ShaunFMichael 3 ปีที่แล้ว +8

    Couple of hours reading universities texts and nope. watch this video twice, plus the previous one and got it. Online universities (and brick) are so behind in teaching.

  • @mariammano1348
    @mariammano1348 2 ปีที่แล้ว +11

    You just nailed it man! Hats off you 🥰 you just make me satisfy about this topic

  • @arushigautam2062
    @arushigautam2062 2 ปีที่แล้ว +10

    Worth appreciating content...
    Cleared my concepts in one go😄

  • @amanbishtxiia3647
    @amanbishtxiia3647 3 ปีที่แล้ว +12

    The content is really good 👍

  • @gabrielaportillo299
    @gabrielaportillo299 2 ปีที่แล้ว +1

    I had no idea this was a khan academy video! this is amazing!

  • @yashbehl8807
    @yashbehl8807 2 ปีที่แล้ว +1

    Amazing, regenerated my interest in the subject.

  • @rippking3167
    @rippking3167 ปีที่แล้ว

    veryyy well ilustrated and well comented!! thanks!

  • @manikantaboddu2197
    @manikantaboddu2197 ปีที่แล้ว +1

    Very useful stuff for engineering students... Thank u soo much sir :)

  • @armaan7194
    @armaan7194 ปีที่แล้ว +1

    You are really a very good teacher... Ur videos are so knowledgeable and time saving👍🏻

  • @josecarlosferreira4942
    @josecarlosferreira4942 ปีที่แล้ว

    This guy is brilliant. Thank you sir!

  • @AkshayKumar-lx5cr
    @AkshayKumar-lx5cr 2 ปีที่แล้ว +1

    Amazing explanation. This is gonna make my day

  • @ashleymariamthomas1120
    @ashleymariamthomas1120 ปีที่แล้ว +1

    Thank you so much for the detailed explanation 😊

  • @vershitayadav7753
    @vershitayadav7753 2 ปีที่แล้ว +1

    love your teachings sir
    and your software as well

  • @missarcane-uy1mt
    @missarcane-uy1mt 5 หลายเดือนก่อน

    idk how to thank u , really amazed by ur teaching

  • @advanceringnewholder
    @advanceringnewholder ปีที่แล้ว

    thanks man, you have answered my questions.

  • @manishasharma6730
    @manishasharma6730 ปีที่แล้ว

    Excellent, this video created my interest in physics....

  • @DeepakSingh-yy1vn
    @DeepakSingh-yy1vn 3 ปีที่แล้ว +7

    Sir ossmmmmm content 🤗🤗🤗. I love the way u teach....
    Sir it's a rqst pls upload solar cell as tomorrow is my pre exam of phy

  • @alonzoball6266
    @alonzoball6266 3 หลายเดือนก่อน

    You made incredible sense than my lecturer and he has one more than an hour video on this and still doesn't make any sense.

  • @surbhiparey2368
    @surbhiparey2368 3 ปีที่แล้ว +1

    Amazing!

  • @spurti
    @spurti 2 ปีที่แล้ว +3

    Ohh the electrons from the negative terminal (electron flow) fills out the holes in p type material. Conversely the electrons from the n type side is reaching towards the positive terminal of the battery so the depletion layer is increased and if we finished this process then the current would not flow in a reverse bias mode.

    • @atomicreactions9201
      @atomicreactions9201 2 ปีที่แล้ว +1

      Exactly. I am learning this topic a the moment, and he confused me lot, that he is doing it the other way arount.

    • @atomicreactions9201
      @atomicreactions9201 2 ปีที่แล้ว

      Oh never mind. I was wrong my self. Because of the charge double layer, which results out of the will of the to potentials to get equivalent, the electrons forming on the p-side are directe moving to the n-side because the first space on the n-side is positivly charged.
      The result in the end is a potenzial difference and a resulting current.

    • @spurti
      @spurti 2 ปีที่แล้ว +1

      @@atomicreactions9201 are you talking about reverse or forward bias mode?? Like I would recommend you to watch a video on diodes by ochem tutor on youtube. So that you get the basic concept and come back here and watch solar cells,photodiode and led.

  • @runzit2007
    @runzit2007 3 ปีที่แล้ว +3

    Excellent

  • @sambhavchaudhary6344
    @sambhavchaudhary6344 2 ปีที่แล้ว +3

    great explanation

  • @jinny8014
    @jinny8014 ปีที่แล้ว

    Thank you for making this easier

  • @raghumandati463
    @raghumandati463 3 ปีที่แล้ว +3

    Content is ever good

  • @heyyounotyouyou3761
    @heyyounotyouyou3761 ปีที่แล้ว

    Man this video was frinking awesome

  • @santhoshkumarb2408
    @santhoshkumarb2408 ปีที่แล้ว +1

    God sent this man 😅 for us guys !

  • @raw_penguin2316
    @raw_penguin2316 10 หลายเดือนก่อน

    Great Video!

  • @najeebqureshi3000
    @najeebqureshi3000 ปีที่แล้ว +3

    Tomorrow is exam of 8th semester Thank you Sir ji! you cleared my concepts even my professor could not clear the concepts in the timeframe of 6 months you did it in 11:39 minutes.
    What a Legend!
    Lots of Love from Pakistan!

  • @zraarali4323
    @zraarali4323 5 หลายเดือนก่อน

    No one can beat these lctrs for sure of khn acdmyy for thiss chpp🤓

  • @srujan797
    @srujan797 7 หลายเดือนก่อน

    Crystal clear sir ❤❤

  • @ruperthowton5091
    @ruperthowton5091 2 ปีที่แล้ว +1

    Nice explanation thanks

  • @TwistedKrizZ33
    @TwistedKrizZ33 ปีที่แล้ว +1

    The best best one

  • @soulmantrajee6683
    @soulmantrajee6683 ปีที่แล้ว

    Nice way of explaining thinks👍🏻

  • @kartikchauhan8939
    @kartikchauhan8939 2 ปีที่แล้ว

    Great work

  • @JJHanna
    @JJHanna ปีที่แล้ว

    Stellar explanation

  • @vedgr8605
    @vedgr8605 2 ปีที่แล้ว

    thanks a lot for these videos

  • @xpanda7112
    @xpanda7112 หลายเดือนก่อน

    thank you very much

  • @jyothi9151
    @jyothi9151 2 ปีที่แล้ว

    the bestt💯

  • @mwerensteijn
    @mwerensteijn ปีที่แล้ว

    Thank you so much!

  • @aakashdewangan7313
    @aakashdewangan7313 ปีที่แล้ว

    excellent!

  • @khadijakaeedbhinderwala6502
    @khadijakaeedbhinderwala6502 2 ปีที่แล้ว

    Awesome video

  • @kannadiga_saleem943
    @kannadiga_saleem943 ปีที่แล้ว

    Very good explanation

  • @techrajix
    @techrajix 4 หลายเดือนก่อน

    It was a great explanation sir

  • @lowisakinson8628
    @lowisakinson8628 2 ปีที่แล้ว

    Thanks alot sir

  • @_Insert_Username
    @_Insert_Username ปีที่แล้ว

    Really great explation

  • @khuuus5994
    @khuuus5994 2 ปีที่แล้ว

    Animations are best source of studies💘

  • @ameeliamajid8140
    @ameeliamajid8140 2 ปีที่แล้ว

    thanks!

  • @rakeshkulkarni4323
    @rakeshkulkarni4323 ปีที่แล้ว

    Logical explanation

  • @olmusic7856
    @olmusic7856 2 ปีที่แล้ว +1

    Tnx a lot

  • @javeriahfahim882
    @javeriahfahim882 ปีที่แล้ว

    Best explanation

  • @sowndaryaravi5285
    @sowndaryaravi5285 2 ปีที่แล้ว

    Very useful

  • @08athakwaninandish16
    @08athakwaninandish16 2 ปีที่แล้ว +2

    विवरण और ग्राफिक्स, दोनों ही बहुत अच्छे हैं।
    Hats off to you dude and to Khan academy!!!

  • @sm-pz8er
    @sm-pz8er 11 หลายเดือนก่อน

    Thanks for the video. Why the current is from right to left not left to right? toward N junction?

  • @jothibaskarn887
    @jothibaskarn887 10 หลายเดือนก่อน

    Very nice

  • @qzorn4440
    @qzorn4440 2 ปีที่แล้ว +1

    is the current flow direction due to the electron movement or the void of an electron hole movement as an electron in a vacuum???

  • @ojaspatil2094
    @ojaspatil2094 ปีที่แล้ว

    beautiful

  • @karlberggren2042
    @karlberggren2042 2 ปีที่แล้ว +6

    Nice video. My only suggestion is that the i v curve should not go to the origin. Even at v=0 you should see significant photo current, I believe.

    • @lewtube6436
      @lewtube6436 9 หลายเดือนก่อน

      I agree -- because the depletion region is still present at v = 0 (albeit a non-expanded one), and it's in this region the current is generated.

  • @niranjan7457
    @niranjan7457 3 ปีที่แล้ว +14

    Sir at 07:43
    You mentioned that we want the current only due to light so we don't use forward biasing (as another current flows)
    But in reverse biasing, a current flows (not due to photons) but it's very small. So we are neglecting that current, right?

    • @radhakrishnajha5084
      @radhakrishnajha5084 2 ปีที่แล้ว +2

      Ofcourse

    • @avijitmudgal7554
      @avijitmudgal7554 2 ปีที่แล้ว +2

      Off course...see the current generated in the depletion layer is enormously small as compared to the current which is generated by light.

    • @debarshidas8596
      @debarshidas8596 2 ปีที่แล้ว +1

      No, I think it is included in dark current

    • @semprocarnage
      @semprocarnage ปีที่แล้ว

      ​@@debarshidas8596ya

  • @beartheburn3863
    @beartheburn3863 3 ปีที่แล้ว +1

    Shouldn't be the positive ion of the depletion region be containing the holes ?? 5: 22

  • @tasneem6427
    @tasneem6427 3 ปีที่แล้ว +5

    Goddamn! This is so good 😳

  • @umabagri2848
    @umabagri2848 2 ปีที่แล้ว +11

    Even if Issac Newton, Albert Einstein would watch you, they would love your way of teaching. ❤❤❤❤❤❤❤

  • @aramugamselvavadivel5262
    @aramugamselvavadivel5262 หลายเดือนก่อน

    what software are you using to explain

  • @lumiluppy8294
    @lumiluppy8294 4 หลายเดือนก่อน

    Hi! What do you mean add a diffuser in photodiode?

  • @oyster4545
    @oyster4545 ปีที่แล้ว

    How much lovely voice he has🥰😅

  • @SD-mc9xm
    @SD-mc9xm 6 หลายเดือนก่อน

    The electron absorbing the energy from the photon sounds like the photoelectric effect

  • @arduinosensor8728
    @arduinosensor8728 ปีที่แล้ว

    Hi, how to calculate a resistor value for a photodiode?

  • @jigyasaagarwal6161
    @jigyasaagarwal6161 ปีที่แล้ว

    Can you tell me the reason of negative current ??

  • @prashantgiri2082
    @prashantgiri2082 3 หลายเดือนก่อน

    Suppose if the light brightness is maximum, then will the current flow or the depletion region will blast...???

  • @anitathomas5506
    @anitathomas5506 3 ปีที่แล้ว

    thanks sir

  • @samikshachauhan6078
    @samikshachauhan6078 ปีที่แล้ว

    Is this same happen in pin photodiode

  • @user-ez9ex8hx6v
    @user-ez9ex8hx6v 6 หลายเดือนก่อน

    Yess

  • @redhoodiestudio
    @redhoodiestudio ปีที่แล้ว

    It makes no sense to me that the free electron would recombine outside of the depletion region, because we apply an electric field with our reverse bias. Or what do I see wrong?

  • @waleedgamerff3079
    @waleedgamerff3079 2 หลายเดือนก่อน

    Waàoo❤❤❤

  • @parmanmshaibani8784
    @parmanmshaibani8784 3 ปีที่แล้ว

    Best content in this term

  • @petermarsh4993
    @petermarsh4993 ปีที่แล้ว

    Dear Sir, I have a problem which you may be able to help me solve. I have a new Solar Panel installation and I want to use it in part to heat my underfloor heating through the electrical conduction wires embedded in my concrete floor. The problem is, when sunlight dims during the day, electricity comes from the grid to maintain a consistent flow of electricity to heat my floor. Grid electricity is expensive and I NEVER want to use grid electricity to heat the floor, only solar derived electricity.
    I was thinking of combining two devices to make a switch that turned on the output to the floor from my solar panels when the sun is shining and turn off current when the sun is not shining. The thought was to use a Photodiode as the current switch that is connected via a low voltage power supply to a solenoid. This solenoid switches off 240V power to my underfloor heating when the solar radiation {and therefore current in the low voltage circuit} drops to below a certain level and stops power going to the heater circuit. If the sun reappears from behind a cloud, the circuit goes back on again.
    What do you think about my problem and do you have any suggestions? Thanks.

  • @vivekthumu8992
    @vivekthumu8992 2 ปีที่แล้ว +1

    I get answer for. my childhood question how bank. machine counts bundles of money in just seconds

  • @nomanaziz804
    @nomanaziz804 3 หลายเดือนก่อน

    Love from Pakistan ❤

  • @va11bhav_rana
    @va11bhav_rana 3 ปีที่แล้ว

    best

  • @sbbarath5802
    @sbbarath5802 3 ปีที่แล้ว +2

    can this be used in automatic doors which open when we go near it??????

    • @tasneem6427
      @tasneem6427 3 ปีที่แล้ว

      We are not light emitting bodies. So I don’t think so 👀

    • @deepanshu564
      @deepanshu564 3 ปีที่แล้ว

      infra-radiation detection is used in heat cameras for automatic doors

    • @Pushed2InsanityYT
      @Pushed2InsanityYT 2 ปีที่แล้ว

      Possibly if you have some bright light shining at the sensor and you happen to block that light when you come near the door, current will decrease, and door can open, but I think this can raise many false alarms. Like what if a fly just cover up the sensor, or something.

  • @yashboss9593
    @yashboss9593 2 ปีที่แล้ว +1

    👍👍👍👍👍

  • @safalgupta6927
    @safalgupta6927 3 ปีที่แล้ว

    Golduuuu

  • @seazaachannel1307
    @seazaachannel1307 2 ปีที่แล้ว

    I want thaisub.

  • @KaranKaran-fw1bt
    @KaranKaran-fw1bt 2 ปีที่แล้ว

    Tomorrow tell it

  • @hrugved005
    @hrugved005 ปีที่แล้ว +1

    Correct the accent! The KHurrent dosent sound so good to listen to.

  • @sohamjadhav5218
    @sohamjadhav5218 2 ปีที่แล้ว

    he sounds like @sauraXD

  • @penumalasunitha14
    @penumalasunitha14 2 ปีที่แล้ว

    Sir, what are used in Solar panels, photodiode or solar cells???

  • @saju2385
    @saju2385 2 ปีที่แล้ว

    Anna sivanesh anna

  • @rishabhsamarwal573
    @rishabhsamarwal573 2 ปีที่แล้ว +3

    Sir if you will teach this in hindi then your growth will become 10x

    • @siddharth8526
      @siddharth8526 2 ปีที่แล้ว +1

      The heck bro, the only few channels that post teaching videos other than Hindi in India. This channel is for indians not for North Indians alone so shut up😡🤬🤬🤬🤬🤬🤬🤬

    • @aditi9069
      @aditi9069 2 ปีที่แล้ว

      @@siddharth8526 exactly!

  • @devendra2003
    @devendra2003 2 ปีที่แล้ว +1

    tum bhagwan ho 💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐💐👌👌💐💐🎂🎂🎂🎂💐💐👌💐💐🎂🎂🎂🎂💐💐💐💐77👌👍😢😊☺️☺️

  • @bdas2267
    @bdas2267 ปีที่แล้ว +1

    Your accent is quite irritating. Please try to speak in Indian accent instead of copying other countries accent. Otherwise videos is good.

  • @raphaelcardoso7927
    @raphaelcardoso7927 2 ปีที่แล้ว

    Very good explanation