How does a Diode Work? A Simple Explanation | How Diodes Work | Electrical4U
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- Опубликовано: 30 янв 2017
- A SIMPLE explanation of a Diode. Learn how a Diode works through diagrams and example. Want to know more? Read the full article on the working principle and types of diodes here: www.electrical4u.com/diode-wo...
A diode is defined as a two-terminal electronic component that only conducts current in one direction (so long as it is operated within a specified voltage level). An ideal diode will have zero resistance in one direction, and infinite resistance in the reverse direction.
Although in the real world, diodes can not achieve zero or infinite resistance. Instead, a diode will have negligible resistance in one direction (to allow current flow), and very high resistance in the reverse direction (to prevent current flow). A diode is effectively like a valve for an electrical circuit.
Semiconductor diodes are the most common type of diode. These diodes begin conducting electricity only if a certain threshold voltage is present in the forward direction (i.e. the “low resistance” direction). The diode is said to be “forward biased” when conducting current in this direction. When connected within a circuit in the reverse direction (i.e. the “high resistance” direction), the diode is said to be “reverse biased”.
The diode is said to be “forward biased” when conducting current in this direction. When connected within a circuit in the reverse direction (i.e. the “high resistance” direction), the diode is said to be “reverse biased”.
Comment below with any additional questions you have. If you enjoyed this video on diodes and want to see more like it, please LIKE and SUBSCRIBE to our RUclips channel.
Thank you for watching!
You can read our full article on the working principle & types of diodes at: www.electrical4u.com/diode-working-principle-and-types-of-diode/
could you tell us the background music you used? It is awesome & hypnotizing.
Background Music is extremely disturbing
Good video, but background music is dominating his voice, unable concentrate, plz change it
Nice exaplational good deplipational leary
Yes. I'm baling out at 0:50. Bye.
Very good explanation! finally understood the biasing in a diode... thanks a lot!
No problem - happy it helped!
One of the best explanation here on YT. Many others does not understand the difference between power source polarity and electric receiving component polarity and semiconductors. The latter do not carry the electrical potential. Maybe they should study how capacitors work and think twice.
Thanks! After watching a number of other video's that tried to explain diodes, I found this one to be the first that clearly explains how the depletion region and electric field forms and works. It helped that you explained that the N- and P-doped material is neutral (has no charge). That explains why a field is formed, and I missed that information in other videos.
You may also refer the books in this reply.
What is a pn junction ?
A pn junction allows current in one direction only. It blocks current in the reverse direction.
When a pn junction is formed, a potential barrier designated Vo comes into existence and is typically around 0.6 to 0.7 volts for silicon junctions.
When the barrier whose Vo is 0.7 volts is disturbed by applying a forward bias of say, 0.6 volts, the current increases and the increase becomes steep for small increments of the forward bias value a little greater than 0.68 volts. Large currents are observed when the forward bias is 0.69 volts which is closer to the barrier voltage of 0.7 volts.
The forward bias can never exceed the potential barrier voltage nor can it bring the barrier down to zero volts. That is the reason you seldom see current vs volt graphs of pn junction diodes beyond a volt or so.
How does the bias remain less than the barrier in an operational diode?
The voltage bias applied drops in the bulk neutral regions of the diode.
The current in a forward bias adjusts to fulfill the conservation of current law and the rate of recombination.
A detailed description of the pn junction with a distinct approach using surface charges, alignment of Fermi levels, creation of the barrier, the distinct processes of diffusion, drift, recombination and the influence of the electric field on the energies of electrons is provided in the following textbooks.
Electrostatics and circuits belong to one science and not two, that of electricity and magnetism. To know how they are unified visit this link
matterandinteractions.org/articles-talks/ and view the article 'A unified treatment of electrostatics and circuits. B. Sherwood and R. Chabay, unpublished. (1999)'
pdf.
For a live demonstration of surface charge and its effects in circuits visit
ruclips.net/video/U7RLg-691eQ/видео.html
For a detailed discussion of surface charge, coulomb's law, electric fields, fields of dipoles and other charge configurations, and parallel plates, and a distinct approach using the surface charge concept in the study of advanced topics of capacitance, currents, conservation of charge, conservation of current, superposition of fields, superposition of potential, simple dc circuit, magnetic fields, magnetic fields of a current element, straight wire, current loop, solenoids, biot-savart law, voltage, voltage source, difference between e.m.f. and potential difference, ideal voltage sources, resistors, how current branches in a parallel circuit, capacitors, inductors, Faraday's law, inductance, ac circuits, transmission lines, Lorentz Force law, motors, generators, p-n junction diodes, electromagnetic waves, antennas and radiation, new electrodynamic theories on the nature of the electric field, see "Electric and Magnetic Interactions" by Chabay and Sherwood
www.matterandinteractions.org
or
Fundamentals of electric theory and circuits by Sridhar Chitta
www.wileyindia.com/fundamentals-of-electric-theory-and-circuits.html
There is a "look inside" feature in the amazon.com webpage of the book "Fundamentals of electric theory and circuits" by Sridhar Chitta with a few pages of Chapter 1 which may be viewed and also which you may swipe left or press < icon to view the foreword, preface and Table of Contents. The contents of the above book by Sridhar Chitta, make a distinct unified approach to electrostatics and a few advanced circuits like coupling signals to amplifiers, lending precision and clarity to the topics which is not found in most text books.
The book comes alongwith a CD with animated power point presentations for all chapters and voltage regulator, RC phase shift oscillators and differential amplifiers included additionally.
For a lecture by Prof Ruth Chabay on surface charge in a simple dc circuit visit
ruclips.net/video/-7W294N_Hkk/видео.html
There is a full set of lectures beginning lecture 13 here on surface charges, electric fields, simple circuits, capacitance, inductance, faraday's law, motional emf, magnetic forces and more topics here
matterandinteractions.org/videos/EM.html
@@sridharchitta7321 thank's
Great job, this is really helpful and convincing.
Thank you very much!
This video finally helped me understand how the depletion region works and why little to no current flows when the diode is reverse biased. I read about it in a book but it was hard to understand.
Thanks.
Wondering explanation .
I saw many videos explaining but this amazing. My concept is clear. I have been searching for the logical explanation of working principle of diode.
yoh...thank you Mr. that's some good explanation
No nonsense straight to point videos like this are the best
The best on junction explanation period
Thank you for your kind words Aimilios! :)
excellent video that i had ever seen
Thanks, really appreciated it, I think I got it.
Thank you from Morocco really it's so helpful ❤️
Thank you for your kind words Oumaima - no worries! :)
Thank you for this helpful video , wizh more success 🙌
Here is the video that shows how to determine the state of diode: ruclips.net/video/bkGy0GrMA-Y/видео.html
Sir, Great one. Which software do you use for formation of video's.
I love it, diodes truly one of a kind ! Best regards
Thank you for your kind words Benjamin! Happy to hear you found our video useful 🙂
Thanks sir, really that is very useful
Best explanation on diode ever!
Good explanation for simple PN JUNCTION DIOD super thank you.
No problem at all Sivakumar! Happy to hear you found the video useful 😄
Nice explanation 👌 thank you sir 👍
I have attempted a simple and intuitive explanation for the diode current dependence on saturation current.
The diode current I includes the saturation current represented by the symbol Io.
The current for p-n junction diode current for an applied voltage V is
I = Io {exp(V/VT) - 1} where
Io = {AqD(p)p(no)}/L(p) + {AqD(n)n(po)}/L(n)
In the expression for Io, 'A' is the area of cross-section of the junction, D(p){D(n)} is the diffusion constant for holes{electrons}, L(p){L(n)} is the diffusion length for holes{electrons} and p(no){n(po)} is the thermal equilibrium concentration of holes{electrons} in the n-type{p-type} material.
Here, Io represents a term which incorporates the thermal equilibrium concentrations of holes and electrons. While diode current I takes into account the applied voltage V, Io does not.
Io is multiplied by a factor {e (exp[V/VT]) -1} dependent on the amount of applied voltage and it is this amount of charge carriers which is injected across a forward biased or reverse biased junction.
When forward biased, the factor {e (exp[V/VT]) -1} increases with more and more biasing voltage and the current increases sharply with bias.
Note: The current in a diode under forward bias and in constant thermal equilibrium is due to the movement of the holes and the electrons moving and recombining on and on and on.
When reverse biased, the factor {e (exp[V/VT]) -1} decreases sharply and settles at Io when the bias is large. Here, what it means is that only the thermal equilibrium concentration of carriers participate in conduction. So, the term saturation current Io.
Space does not permit me to explain more here but you may refer to the textbook 4 mentioned below.
The conduction processes of p-n junctions can be easily understood if Current is understood properly by taking a unified approach to electrostatics and circuits.
Electrostatics and circuits belong to one science, not two.
These are discussed usually separately in textbooks and science and engineering courses.
Watch the two videos listed below to learn about current and the conduction process and surface charges (using a unified approach to electrostatics and circuits) which set up the electric field whose line integral is the potential difference. The battery produces the emf.
The last frame of video #1 lists textbooks which discuss all these topics in more detail.
1. ruclips.net/video/REsWdd76qxc/видео.html
2. ruclips.net/video/8BQM_xw2Rfo/видео.html
I have discussed the exact idea on the relation between diode current and saturation current in detail in Chapter 9 and Appendix E of textbook 4 listed in the video #1.
Also explained in the textbook 4 is why the potential barrier of an operational diode can never be made 'zero'.
Thank you sir...
incredible!! Maybe the best video on diodes that I've seen so far
great explanation
Amazing and best explanation on RUclips
Thank you for your kind words! :)
I was skeptical given the format, but damn this is precise.
Very good sharing 👍🏻
Thank you sooo much that was very useful .. Im Arabic from Iraq🇮🇶
Thanks so much man
Good explained!Nice Sir.
Thankyou so much
Good video thank you
Best explanation on youtube
Great explanation.
just awesome
4:26 you said applied voltage > forward bias voltage will make currents flow, but why is that when you said that when there is more applied voltage the diode will behave as an open switch.
Awesome!
Good explanation
This guy draws the best circles
감사합니다~
very good
and thanks
Voice of a teacher.
Thank you Selvam 🤓
lovely Video clearified all my douts
Thank you for your kind words! :)
well explained
v nice explain
Great experience with excellent
Some of the othe "specialists" (who dont get a slightest idea) show the potential current inside semiconductiors flow thru the whole circuit what is WRONG. I like this tutorial. It very good.
Readme .txt I think there is a mistake here. He is taking about the depletion region not the whole diode.
Yeah , great exp , but i really hate digital voice over and stupid repetitious, distracting music..
Brilliant video S Ghosh. Animation looked like calligraphy. Which software did you use to create this video? How did you make this video?
Thankyou
From -Bangladesh
This video really saved me it's around my 20th and I finally understood it. Thanks! However, I've got a question. Why does the junction act as a barrier??
When electrons flow from N to P,and holes from P to N, after a point of time there are so many electrons in Ptype that they actually repel more electrons from coming in thus creating a barrier,similarly holes get form a positive charge in Ntype after a point of time and that repels more holes from coming in.Here the main concept is like charges repel
Thanks 🙏 ❤
Amazing videos
Please give more videos
We will - thank you for your kinds words Shazia 😊
Onek Dhonyobaad
Well explained
Awsome..!
Very good sir this is education.
Great job ever
Thanks, Acceptable easy theory with nice video, very good. BTW i want that music, could someone tell me what is the music title? thanks.
Thanks sir
In reverse bias.. about the reverse satuaration current. Is it from n to p? The diagram in the video is drawn the opposite
we can't combine a ptype and n type semiconductor to form a pn junction diode bcz of surface irregularities.
Best vedio ♥️ ♥️♥️♥️♥️♥️♥️♥️♥️♥️♥️ no words to say thanks
No worries at all! Thank you for your kind words, I'm glad you found it useful 🤓
Thanks
Nice video
many thanks
No worries at all Mohanad :)
beautiful
Awesome sir
Best video on pn junction
Thank you for your kind words Amarnath :)
Mind blowing
very nice vide
nice
Sir can you tell about that battery positive terminal is high potential (electrons) so how can it repulse p junction in this circuit pls tell me what is happening there
nice video
Nice
at 3:03 their is a mistake because barrier potential is from n type to p type
absolutely it is good
thanks🌹
No problem Ragad!
Great
In the depletion layer
Some electrons migrate from p - type but Y it does not moves further in n-type and y the hole created in n-type cant attract further electrons
thank u
No problem Khawaja :)
I love this thanks
Please tell me how you make this video
Is there any mistake about the direction of the barrier potential ? I think it must be the opposite direction, or am I wrong ?
You caught it! actually, the direction you meant is of the electrical field and since E = - grad V, the potential difference direction should be the opposite so it is correct then. But it's a brilliant catch :)
Nguyễn Duy Anh yeah you're right
You mean electric field as told by pfesd but in the video, the are showing di-pole moment -ve to +ve
FU conventional flow Theory
I think u r correct
Good video, I think the HAL 9000 would have been a better narraror.
Good video but voice is not Good
We will try and improve for next time! :)
Thank you for the feedback Ganesh! We will try to improve this in future :)
That's about as good as text-to-speech gets.
@@kiransrinivasan6370 better than having heavy accent making it hard to understand for some folks. I didn't fully understand it but will keep watching it till I do. Thanks for the video.
Is direction of barrier potential is correct??
Good sir please update concepts in ece branch b.tech
Supper sir
I think the electric field direction in your depletion layer might be backwards
I like the music ^__^
we dont actually join ptype and ntype because then due to surface irregularities current wouldnt flow but rather we dope the same material.PLEASE CORRECCT ME IF I M WRONG
Good sir
Thank you Raju :)
Right on money
How you create that video please tell me..
Steal a robot
@@3dvisiongamer213 How to steal Robot, please tell me
حبيبي يا سيد
How is there still ions in the depletion region? I thought it was supposed to be neutral?
Those ions are the boron/phosphorus atoms, not the silicon ones. They need one more/less electron than the saturated crystal grid of silicon has.
isn't holes the empty space on atom orbits ? why is there holes without the atom structures themself ? and how do they leave their orbits and roam freely in a solid without their orbits ?
I had the exact same question in mind
this is supposed to be a dopped semi conductor
this is supposed to be a dopped semi conductor
❤❤❤
Right direction flow
Bad voice but good explanation :D