Forward biasing a PN junction | Class 12 (India) | Physics | Khan Academy

In this video, we will attach metallic contacts at the end of the PN and provide a voltage across it. When we connect P side to Positive and N side to negative, we call it forward biasing.

Class 12 Semiconductors: We cannot imagine our life without computers today. But what makes a computer tick? What's making this technology grow at such an exponential rate? It's all due to semiconductors. As unbelievable as that might sound, altering the properties of semiconductors allows us to build these computers. In this topic, we will explore the world of semiconductors. It's a journey from what semiconductors are all the way to creating building blocks of these computers.

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!

Created by Mahesh Shenoy

[nagarmalsharma]

The best explanation of semiconductors on the whole internet, never understood this concept, but you made it really intuitive, thanks!

[Funchoz_learn]

Superb video quality ... This man has put his heart and soul to it

[osamazahid]

your lecture Answered my lot misconception, you rock the stage!

[cradleblaze]

Damn sir .... What a detailed analysis of semiconductor for jee preparation

[ishitachadha]

You are by far the best animator. I can actually believe and visualize what is written in the book because of you. Please keep making many more videos:)
You really helped me out!

[anushkavora]

one of the best videos i have ever seen out there. so simply explained with the right gear, everything is perfect about it and super easy to understand

[seemabharti]

I have a question
If in forward biasing the electrons flow from n type to p type region
Then shouldn't the depletion region increase.
And electron may recombine again with holes, like they did when the depletion region was initially formed

[prateeksharma]

Sir why are they not recombining and increasing the depletion region when you are connecting it to a battery.

[nehapal]

Made me speechless... Amazing
Wish all teachers should like you

[killiyaswanthkumar]

sir, your way of teaching is so great, pls clarify my doubt/ when ext electric field is applied from p to n type then diffusion current increases, that doesnt destroy the charge carriers and increases internal electric field from n to p type which further increses the barrier width?

[mariaa]

Great! It would be also nice to see band diagrams associated to this pictures in the video. Like the ones in previous videos.

[SIMRAN-kzdw]

In addition to ur extraordinary teaching of vocabulary is excellent as well.
Like "All hell breaks loose "
"Diffusion current sky rocket's "
Plz teach us English too amazing sir

[ishakatira]

Doesn't the rate of recombination now increase as more holes and electrons are now moving?

[harshchoudharyredrose]

I wonder which app he uses for the videos...amazing

[muditagarwal]

The most productive 6 mins of my day today!

[suchitrasridhar]

This is a great video. I just wish there were more Khan Academy videos aligned to CBSE curriculum.

[Pursuit-of-lyf]

This video is great to conceptualise the PN junction mechanism.. i have just one doubt.. plz clarify it.. as u earlier said in previous videos, diffusion would expose the charged ions B- and P+ so with time drift motion increases due to minority charge carriers due to depletion region?? Isn't it?? Or is it just about the dominating factor? That here depletion region goes down inturn increasing diffusion current rather than contributing to drift motion?

[lollopes]

Why is the diffusion current increasing when you apply a forward bias ? Drift currents means that the motion of charges is due to an electric field while Diffusion is caused by difference in concentration. When you apply a forward bias you create an applied electric field across the junction that will make the carries DRIFT to the opposite side not DIFFUSE.

[abdullahbnl]

Your notes available? If available where to find them...reallly besttt teacher ever now a month left to my exams, no time to write lecutres as I've 3 days to prepare I wish O had find them before😢😢😢😢

[VenkatasaitejeshAmbati]

bro actually holes are vacant spaces as you said only the electrons will be crossing the barrier but not the holes .


Holes in p type are present in the valence band of p type wheras electrons in n type are in conduction band so to reach the valence band of p type they have to first reach conduction band of p type which has very few electrons(which are minority carriers of p type) and then loose energy to goto valence band to fill the vacant spaces.