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

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  • Опубліковано 25 сер 2024

КОМЕНТАРІ • 126

  • @personanongrata8690
    @personanongrata8690 3 роки тому +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 роки тому

      *electronics

    • @adeebahmed1067
      @adeebahmed1067 Рік тому +3

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

  • @AJ-td1sb
    @AJ-td1sb 2 роки тому +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 роки тому +52

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

  • @divyamkumarpandey7749
    @divyamkumarpandey7749 3 роки тому +22

    Please add this video to the semiconductors playlist

  • @mariammano1348
    @mariammano1348 2 роки тому +11

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

  • @arushigautam2062
    @arushigautam2062 2 роки тому +10

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

  • @amanbishtxiia3647
    @amanbishtxiia3647 3 роки тому +12

    The content is really good 👍

  • @ShaunFMichael
    @ShaunFMichael 3 роки тому +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.

  • @TwistedKrizZ33
    @TwistedKrizZ33 Рік тому +1

    The best best one

  • @spurti
    @spurti 2 роки тому +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 роки тому +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 роки тому

      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 роки тому +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.

  • @gabrielaportillo299
    @gabrielaportillo299 2 роки тому +1

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

  • @alv9
    @alv9 День тому

    Very helpful! Thank you very much!

  • @sambhavchaudhary6344
    @sambhavchaudhary6344 2 роки тому +3

    great explanation

  • @DeepakSingh-yy1vn
    @DeepakSingh-yy1vn 3 роки тому +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

  • @runzit2007
    @runzit2007 3 роки тому +3

    Excellent

  • @santhoshkumarb2408
    @santhoshkumarb2408 Рік тому +1

    God sent this man 😅 for us guys !

  • @manikantaboddu2197
    @manikantaboddu2197 Рік тому +1

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

  • @raghumandati463
    @raghumandati463 3 роки тому +3

    Content is ever good

  • @armaan7194
    @armaan7194 Рік тому +1

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

  • @yashbehl8807
    @yashbehl8807 2 роки тому +1

    Amazing, regenerated my interest in the subject.

  • @ashleymariamthomas1120
    @ashleymariamthomas1120 Рік тому +1

    Thank you so much for the detailed explanation 😊

  • @missarcane-uy1mt
    @missarcane-uy1mt 8 місяців тому

    idk how to thank u , really amazed by ur teaching

  • @amanuelabbittee4511
    @amanuelabbittee4511 2 місяці тому

    God bless you, man❤❤❤

  • @AkshayKumar-lx5cr
    @AkshayKumar-lx5cr 2 роки тому +1

    Amazing explanation. This is gonna make my day

  • @manishasharma6730
    @manishasharma6730 Рік тому

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

  • @vershitayadav7753
    @vershitayadav7753 2 роки тому +1

    love your teachings sir
    and your software as well

  • @alonzoball6266
    @alonzoball6266 6 місяців тому

    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.

  • @xpanda7112
    @xpanda7112 4 місяці тому

    thank you very much

  • @rippking3167
    @rippking3167 Рік тому

    veryyy well ilustrated and well comented!! thanks!

  • @zraarali4323
    @zraarali4323 8 місяців тому

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

  • @najeebqureshi3000
    @najeebqureshi3000 Рік тому +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!

  • @tasneem6427
    @tasneem6427 3 роки тому +5

    Goddamn! This is so good 😳

  • @techrajix
    @techrajix 7 місяців тому

    It was a great explanation sir

  • @karlberggren2042
    @karlberggren2042 2 роки тому +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 Рік тому

      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.

  • @08athakwaninandish16
    @08athakwaninandish16 2 роки тому +2

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

  • @josecarlosferreira4942
    @josecarlosferreira4942 Рік тому

    This guy is brilliant. Thank you sir!

  • @advanceringnewholder
    @advanceringnewholder Рік тому

    thanks man, you have answered my questions.

  • @ruperthowton5091
    @ruperthowton5091 2 роки тому +1

    Nice explanation thanks

  • @heyyounotyouyou3761
    @heyyounotyouyou3761 Рік тому

    Man this video was frinking awesome

  • @anamikapratiyush7364
    @anamikapratiyush7364 2 місяці тому

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

  • @khuuus5994
    @khuuus5994 2 роки тому

    Animations are best source of studies💘

  • @jinny8014
    @jinny8014 Рік тому

    Thank you for making this easier

  • @niranjan7457
    @niranjan7457 3 роки тому +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 роки тому +2

      Ofcourse

    • @avijitmudgal7554
      @avijitmudgal7554 2 роки тому +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 роки тому +1

      No, I think it is included in dark current

    • @semprocarnage
      @semprocarnage Рік тому

      ​@@debarshidas8596ya

  • @jothibaskarn887
    @jothibaskarn887 Рік тому

    Very nice

  • @olmusic7856
    @olmusic7856 2 роки тому +1

    Tnx a lot

  • @rakeshkulkarni4323
    @rakeshkulkarni4323 Рік тому

    Logical explanation

  • @surbhiparey2368
    @surbhiparey2368 3 роки тому +1

    Amazing!

  • @srujan797
    @srujan797 10 місяців тому

    Crystal clear sir ❤❤

  • @JJHanna
    @JJHanna Рік тому

    Stellar explanation

  • @soulmantrajee6683
    @soulmantrajee6683 Рік тому

    Nice way of explaining thinks👍🏻

  • @qzorn4440
    @qzorn4440 2 роки тому +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???

  • @kannadiga_saleem943
    @kannadiga_saleem943 Рік тому

    Very good explanation

  • @mwerensteijn
    @mwerensteijn Рік тому

    Thank you so much!

  • @javeriahfahim882
    @javeriahfahim882 Рік тому

    Best explanation

  • @sm-pz8er
    @sm-pz8er Рік тому

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

  • @raw_penguin2316
    @raw_penguin2316 Рік тому

    Great Video!

  • @SD-mc9xm
    @SD-mc9xm 9 місяців тому

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

  • @aakashdewangan7313
    @aakashdewangan7313 Рік тому

    excellent!

  • @beartheburn3863
    @beartheburn3863 3 роки тому +1

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

  • @vedgr8605
    @vedgr8605 2 роки тому

    thanks a lot for these videos

  • @umabagri2848
    @umabagri2848 2 роки тому +11

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

  • @lumiluppy8294
    @lumiluppy8294 7 місяців тому

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

  • @jyothi9151
    @jyothi9151 3 роки тому

    the bestt💯

  • @lowisakinson8628
    @lowisakinson8628 3 роки тому

    Thanks alot sir

  • @khadijakaeedbhinderwala6502
    @khadijakaeedbhinderwala6502 2 роки тому

    Awesome video

  • @user-ez9ex8hx6v
    @user-ez9ex8hx6v 9 місяців тому

    Yess

  • @prashantgiri2082
    @prashantgiri2082 6 місяців тому

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

  • @ameeliamajid8140
    @ameeliamajid8140 3 роки тому

    thanks!

  • @akhilseelam3741
    @akhilseelam3741 2 місяці тому

    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.

  • @kartikchauhan8939
    @kartikchauhan8939 3 роки тому

    Great work

  • @oyster4545
    @oyster4545 Рік тому

    How much lovely voice he has🥰😅

  • @sowndaryaravi5285
    @sowndaryaravi5285 3 роки тому

    Very useful

  • @ojaspatil2094
    @ojaspatil2094 2 роки тому

    beautiful

  • @samikshachauhan6078
    @samikshachauhan6078 Рік тому

    Is this same happen in pin photodiode

  • @jigyasaagarwal6161
    @jigyasaagarwal6161 Рік тому

    Can you tell me the reason of negative current ??

  • @vivekthumu8992
    @vivekthumu8992 2 роки тому +1

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

  • @aramugamselvavadivel5262
    @aramugamselvavadivel5262 4 місяці тому

    what software are you using to explain

  • @anitathomas5506
    @anitathomas5506 3 роки тому

    thanks sir

  • @waleedgamerff3079
    @waleedgamerff3079 5 місяців тому

    Waàoo❤❤❤

  • @nomanaziz804
    @nomanaziz804 6 місяців тому

    Love from Pakistan ❤

  • @Chillandrelax2475
    @Chillandrelax2475 Рік тому

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

  • @redhoodiestudio
    @redhoodiestudio Рік тому

    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?

  • @rishabhsamarwal573
    @rishabhsamarwal573 2 роки тому +4

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

    • @siddharth8526
      @siddharth8526 2 роки тому +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 роки тому

      @@siddharth8526 exactly!

  • @sbbarath5802
    @sbbarath5802 3 роки тому +2

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

    • @tasneem6427
      @tasneem6427 3 роки тому

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

    • @deepanshu564
      @deepanshu564 3 роки тому

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

    • @Pushed2InsanityYT
      @Pushed2InsanityYT 2 роки тому

      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.

  • @KaranKaran-fw1bt
    @KaranKaran-fw1bt 2 роки тому

    Tomorrow tell it

  • @parmanmshaibani8784
    @parmanmshaibani8784 3 роки тому

    Best content in this term

  • @va11bhav_rana
    @va11bhav_rana 3 роки тому

    best

  • @yashboss9593
    @yashboss9593 2 роки тому +1

    👍👍👍👍👍

  • @petermarsh4993
    @petermarsh4993 Рік тому

    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.

  • @safalgupta6927
    @safalgupta6927 3 роки тому

    Golduuuu

  • @seazaachannel1307
    @seazaachannel1307 2 роки тому

    I want thaisub.

  • @hrugved005
    @hrugved005 Рік тому +1

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

  • @saju2385
    @saju2385 2 роки тому

    Anna sivanesh anna

  • @sohamjadhav5218
    @sohamjadhav5218 2 роки тому

    he sounds like @sauraXD

  • @devendra2003
    @devendra2003 2 роки тому +1

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

  • @penumalasunitha14
    @penumalasunitha14 3 роки тому

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

  • @bdas2267
    @bdas2267 Рік тому +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 роки тому

    Very good explanation