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

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  • Опубликовано: 12 сен 2024

Комментарии • 128

  • @personanongrata8690
    @personanongrata8690 3 года назад +96

    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 года назад

      *electronics

    • @adeebahmed1067
      @adeebahmed1067 Год назад +3

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

  • @AJ-td1sb
    @AJ-td1sb 2 года назад +35

    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.

  • @andreadanniballe5013
    @andreadanniballe5013 3 года назад +52

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

  • @divyamkumarpandey7749
    @divyamkumarpandey7749 3 года назад +22

    Please add this video to the semiconductors playlist

  • @spurti
    @spurti 2 года назад +4

    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 года назад +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 года назад

      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 года назад +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.

  • @mariammano1348
    @mariammano1348 2 года назад +11

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

  • @arushigautam2062
    @arushigautam2062 2 года назад +10

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

  • @DeepakSingh-yy1vn
    @DeepakSingh-yy1vn 3 года назад +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

  • @amanbishtxiia3647
    @amanbishtxiia3647 3 года назад +12

    The content is really good 👍

  • @ShaunFMichael
    @ShaunFMichael 3 года назад +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.

  • @niranjan7457
    @niranjan7457 3 года назад +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 года назад +2

      Ofcourse

    • @avijitmudgal7554
      @avijitmudgal7554 2 года назад +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 года назад +1

      No, I think it is included in dark current

    • @semprocarnage
      @semprocarnage Год назад

      ​@@debarshidas8596ya

  • @gabrielaportillo299
    @gabrielaportillo299 2 года назад +1

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

  • @karlberggren2042
    @karlberggren2042 2 года назад +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 Год назад

      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.

  • @armaan7194
    @armaan7194 Год назад +1

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

  • @manikantaboddu2197
    @manikantaboddu2197 Год назад +1

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

  • @yashbehl8807
    @yashbehl8807 2 года назад +1

    Amazing, regenerated my interest in the subject.

  • @akhilseelam3741
    @akhilseelam3741 2 месяца назад

    00:02 Photodiodes convert light to electricity and are used in detecting brightness
    01:39 Reverse biasing in photodiodes limits current and widens depletion region.
    03:08 Light absorption in semiconductors creates electron-hole pairs
    04:32 Light absorption generates current in semiconductors
    06:01 Photodiodes detect brightness using reverse bias.
    07:27 Photodiodes work in reverse bias to ensure current is only due to light.
    08:54 Current generated by photodiodes is independent of voltage after a certain point due to the number of electron-hole pairs formed by the light.
    10:15 Photodiodes can generate a tiny current even in absence of light due to thermal energy.

  • @08athakwaninandish16
    @08athakwaninandish16 2 года назад +2

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

  • @ashleymariamthomas1120
    @ashleymariamthomas1120 Год назад +1

    Thank you so much for the detailed explanation 😊

  • @vershitayadav7753
    @vershitayadav7753 2 года назад +1

    love your teachings sir
    and your software as well

  • @TekCroach
    @TekCroach 2 дня назад

    The bank note counter example... is that the way it really works? I don't think so. anyway, a very good explanation on the photodiode. thanks.

  • @alv9
    @alv9 19 дней назад

    Very helpful! Thank you very much!

  • @AkshayKumar-lx5cr
    @AkshayKumar-lx5cr 2 года назад +1

    Amazing explanation. This is gonna make my day

  • @sambhavchaudhary6344
    @sambhavchaudhary6344 2 года назад +3

    great explanation

  • @najeebqureshi3000
    @najeebqureshi3000 Год назад +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!

  • @missarcane-uy1mt
    @missarcane-uy1mt 9 месяцев назад

    idk how to thank u , really amazed by ur teaching

  • @qzorn4440
    @qzorn4440 2 года назад +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???

  • @santhoshkumarb2408
    @santhoshkumarb2408 Год назад +1

    God sent this man 😅 for us guys !

  • @manishasharma6730
    @manishasharma6730 Год назад

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

  • @tasneem6427
    @tasneem6427 3 года назад +5

    Goddamn! This is so good 😳

  • @raghumandati463
    @raghumandati463 3 года назад +3

    Content is ever good

  • @beartheburn3863
    @beartheburn3863 3 года назад +1

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

  • @sm-pz8er
    @sm-pz8er Год назад

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

  • @rippking3167
    @rippking3167 Год назад

    veryyy well ilustrated and well comented!! thanks!

  • @TwistedKrizZ33
    @TwistedKrizZ33 Год назад +1

    The best best one

  • @advanceringnewholder
    @advanceringnewholder Год назад

    thanks man, you have answered my questions.

  • @techrajix
    @techrajix 7 месяцев назад

    It was a great explanation sir

  • @anamikapratiyush7364
    @anamikapratiyush7364 3 месяца назад

    Excellent explanation, however the bossing in forward condition is not correct

  • @josecarlosferreira4942
    @josecarlosferreira4942 Год назад

    This guy is brilliant. Thank you sir!

  • @runzit2007
    @runzit2007 3 года назад +3

    Excellent

  • @alonzoball6266
    @alonzoball6266 7 месяцев назад

    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.

  • @amanuelabbittee4511
    @amanuelabbittee4511 3 месяца назад

    God bless you, man❤❤❤

  • @zraarali4323
    @zraarali4323 9 месяцев назад

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

  • @jinny8014
    @jinny8014 Год назад

    Thank you for making this easier

  • @heyyounotyouyou3761
    @heyyounotyouyou3761 Год назад

    Man this video was frinking awesome

  • @lumiluppy8294
    @lumiluppy8294 7 месяцев назад

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

  • @prashantgiri2082
    @prashantgiri2082 6 месяцев назад

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

  • @umabagri2848
    @umabagri2848 2 года назад +11

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

  • @soulmantrajee6683
    @soulmantrajee6683 Год назад

    Nice way of explaining thinks👍🏻

  • @ruperthowton5091
    @ruperthowton5091 2 года назад +1

    Nice explanation thanks

  • @xpanda7112
    @xpanda7112 5 месяцев назад

    thank you very much

  • @JJHanna
    @JJHanna Год назад

    Stellar explanation

  • @srujan797
    @srujan797 11 месяцев назад

    Crystal clear sir ❤❤

  • @vedgr8605
    @vedgr8605 2 года назад

    thanks a lot for these videos

  • @aramugamselvavadivel5262
    @aramugamselvavadivel5262 5 месяцев назад

    what software are you using to explain

  • @khuuus5994
    @khuuus5994 2 года назад

    Animations are best source of studies💘

  • @surbhiparey2368
    @surbhiparey2368 3 года назад +1

    Amazing!

  • @mwerensteijn
    @mwerensteijn Год назад

    Thank you so much!

  • @SD-mc9xm
    @SD-mc9xm 10 месяцев назад

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

  • @olmusic7856
    @olmusic7856 2 года назад +1

    Tnx a lot

  • @rakeshkulkarni4323
    @rakeshkulkarni4323 Год назад

    Logical explanation

  • @jigyasaagarwal6161
    @jigyasaagarwal6161 Год назад

    Can you tell me the reason of negative current ??

  • @sbbarath5802
    @sbbarath5802 3 года назад +2

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

    • @tasneem6427
      @tasneem6427 3 года назад

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

    • @deepanshu564
      @deepanshu564 3 года назад

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

    • @Pushed2InsanityYT
      @Pushed2InsanityYT 2 года назад

      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.

  • @kannadiga_saleem943
    @kannadiga_saleem943 Год назад

    Very good explanation

  • @DeuryMota
    @DeuryMota 10 месяцев назад

    Yess

  • @samikshachauhan6078
    @samikshachauhan6078 Год назад

    Is this same happen in pin photodiode

  • @raw_penguin2316
    @raw_penguin2316 Год назад

    Great Video!

  • @Chillandrelax2475
    @Chillandrelax2475 Год назад

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

  • @javeriahfahim882
    @javeriahfahim882 Год назад

    Best explanation

  • @lowisakinson8628
    @lowisakinson8628 3 года назад

    Thanks alot sir

  • @aakashdewangan7313
    @aakashdewangan7313 Год назад

    excellent!

  • @petermarsh4993
    @petermarsh4993 Год назад

    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.

  • @jothibaskarn887
    @jothibaskarn887 Год назад

    Very nice

  • @redhoodiestudio
    @redhoodiestudio Год назад

    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?

  • @kartikchauhan8939
    @kartikchauhan8939 3 года назад

    Great work

  • @khadijakaeedbhinderwala6502
    @khadijakaeedbhinderwala6502 2 года назад

    Awesome video

  • @ameeliamajid8140
    @ameeliamajid8140 3 года назад

    thanks!

  • @jyothi9151
    @jyothi9151 3 года назад

    the bestt💯

  • @sowndaryaravi5285
    @sowndaryaravi5285 3 года назад

    Very useful

  • @ojaspatil2094
    @ojaspatil2094 2 года назад

    beautiful

  • @oyster4545
    @oyster4545 Год назад

    How much lovely voice he has🥰😅

  • @vivekthumu8992
    @vivekthumu8992 2 года назад +1

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

  • @hrugved005
    @hrugved005 Год назад +1

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

  • @rishabhsamarwal573
    @rishabhsamarwal573 2 года назад +4

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

    • @siddharth8526
      @siddharth8526 2 года назад +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 года назад

      @@siddharth8526 exactly!

  • @anitathomas5506
    @anitathomas5506 3 года назад

    thanks sir

  • @nomanaziz804
    @nomanaziz804 7 месяцев назад

    Love from Pakistan ❤

  • @parmanmshaibani8784
    @parmanmshaibani8784 3 года назад

    Best content in this term

  • @waleedgamerff3079
    @waleedgamerff3079 6 месяцев назад

    Waàoo❤❤❤

  • @penumalasunitha14
    @penumalasunitha14 3 года назад

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

  • @KaranKaran-fw1bt
    @KaranKaran-fw1bt 2 года назад

    Tomorrow tell it

  • @va11bhav_rana
    @va11bhav_rana 3 года назад

    best

  • @yashboss9593
    @yashboss9593 2 года назад +1

    👍👍👍👍👍

  • @seazaachannel1307
    @seazaachannel1307 2 года назад

    I want thaisub.

  • @sohamjadhav5218
    @sohamjadhav5218 2 года назад

    he sounds like @sauraXD

  • @safalgupta6927
    @safalgupta6927 3 года назад

    Golduuuu

  • @saju2385
    @saju2385 2 года назад

    Anna sivanesh anna

  • @devendra2003
    @devendra2003 2 года назад +1

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

  • @bdas2267
    @bdas2267 Год назад +1

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

    • @malissa8243
      @malissa8243 8 дней назад +1

      He copying only few words pronunciation which are easier that makes his accent irritating

  • @raphaelcardoso7927
    @raphaelcardoso7927 2 года назад

    Very good explanation