C8 Why is Silicon a Semiconductor? [HL IB Chemistry]

The correct frequency of light (or heat) moves some of the bonded silicon electrons into the conduction band. An applied potential difference with move them forming a current.

[@arvomusic]

I didn’t know where I could leave you this comment so I decided to do so in what appears to be your latest contribution. Richard Thornley, I couldn’t thank you enough. In the end I got 7 in IB Chemistry and it wouldn’t have been remotely possible without your videos and teachings. Now, I am able to study in the UK thanks to my IB score. You should be extremely proud of your work and you must know your videos are not only helpful but fun to watch. Thank you again and best of luck with your life projects.

[@arvomusic]

Please do let me know if you want me to post this somewhere else so that your boss can see it or if I can help in any other way. Cheers

[@ibchemvids]

Wow - a 7 is pretty pretty good. I only got a "C" in my high school chemistry!

[@jesussatan5937]

its possible stop hating!

[@UmerFarooq-dg8dk]

@@jesussatan5937 lol that's not hating

[@kylajayapurna9058]

thanku so much i spent AGES trying to figure this out TT

[@MGPL_]

lol, i feel like the whole video was made just to line up that joke at the end. brilliant.

[@ChrisLehtoF16]

Great video thanks.

[@yejieke92]

Finally i understand it
Thanks

[@buswell45]

Hi Richard, is there a specific temperature that a semi-conductor reaches its maximum conductivity? I say this because I track my rooftop solar panel output and they do not perform as well on the hottest Aussie summer days. Also, cheers for these resources - this flipped classroom revolution seems to be gaining momentum...

[@ibchemvids]

Google "flipping failure" to see my crash-and-burn attempt at flipping. Increased temperature decreases the band gap - so I suppose a smaller gap is harder for the electrons to fill...?

[@buswell45]

Yep I've seen the article. Flipping is yet to get a grip over here. Thanks for the clarification on band gap/temp - might warrant further investigation. We teach the entire HL course in 6 months so there is only so much you can do as a teacher. Also, these videos have acted as my 'mentor' due to the lack of experienced IB teachers to leverage off. A big, big thanks. And on a side note - I was also a 'C' chemistry student in school and now in my 30's I can't get enough of the stuff. There's hope for everyone.

[@seragheiba5087]

I did my physics IA on this! Although I don't know if there's a theoretical maximum to the conductivity of a semi-conductor, I know that the reason why your solar panel output decreases as temperature rises isn't because of current. It's because of voltage. As temperature rises, voltage drops by a bigger amount than current increases and therefore brings down the overall power output, since P=VI. The reason voltage drops is indeed because the band gap decreases (as Mr. Thornley already said), and so there is a smaller potential difference between the valence band and conduction band of the semiconducting material for the electrons to jump between, which basically means a smaller voltage. FYI, solar panels are supposed to have a temperature coefficient rating, which tells you by how much you should expect power output to drop for each increase in degree Celsius of temperature (as felt by the solar panel). It's usually around -0.4% per degree C, so on the hottest Aussie summer days when the surface temperature of the solar panel can reach up to 50 C even, you can expect power output to drop by 10% or more!

[@MMTRINATHSOLASA]

Awesome

[@teezsultanhamraa5889]

هتعوضنى ازاى

[@robertmurray2293]

is wet silicon conductive

[@ibchemvids]

Silicon does not dissolve in water, but maybe electricity would pass through the water if it contained some dissolved salts or CO2

[@Jung-lee-kook]

..

[@megag52]

gotta give it a dislike for the ending