What is a semiconductor? Chemistry Calendar, September: Communication

Uploaded by MoleCluesTV on 07.11.2011


Well, we sure use many different ways to communicate.
But only in recent years have we had the technology
to communicate with anyone we want, almost anywhere on the Planet.
And with the touch of a finger, we can access information about nearly anything.
But I tell you what, without an understanding of chemistry
and how we can use the properties of the chemical elements,
none of this would have been possible today.

Well, I haven’t told anyone yet, but I decided to take work out here today
because it’s a beautiful day.
But how is it that I can be out here in the middle of nowhere
and still be able to communicate with pretty much anyone on the Planet?
Well, this got me a little curious about the background of this new technology,
so I did a few searches and they all seem to take me back to this one place in California.
You might have heard of it before, it’s called Silicon Valley.
This got me even more curious.
How is it that one of the main centers for modern technology and communication
is named after one of the elements in the periodic table?
This is what we’re going to find out!

Hey, are you there?
Yes, I’m right here
and I think I have someone here who can help us with this one…  
Okay, call me when you know more!
My name is Chris Knee.
I’m a materials chemist and I work as an associate professor
at the University of Gothenburg.
Why is it called Silicon Valley?
Okay, Silicon Valley gets its name from the chemical element silicon
and it’s used in semiconductor industry.
A good way to understand what a semiconductor is,
is to consider an everyday example of a cable.
In such a cable you have a metal component
through which the electrons can flow very easily, it’s a good conductor.
And the metal is surrounded by, in this case, a particular plastic
that is very poor at conducting electrons. It's an insulator.
And a semiconductor has electrical conduction that is midway between
a very good conductor, such as a metal,
and a very poor conductor, such as an insulator.
So for semiconductors, like silicon, the electric conductivity
is somewhere in between a conductor and an insulator.
By exploiting these properties scientists developed
very small transistors on silicon chips.
A transistor is a device that can regulate an electric signal.
The semiconductor element of the transistor is then used as a switch,
where the strength of an incoming current is deciding whether the switch
is going to be ON of OFF, or 1 or 0,
which forms the basis for all the modern technology that we have.
So one of the key things to understand is that the technology for computers
was already established.
But what silicon and the use of semiconductors allowed
is to make everything much smaller.
Supercomputers were huge, the size of a house,
but now with the silicon revolution then you could miniaturize all these transistors
and you could make much more powerful computers which occupied much less space.

Okay, I’m back.
So the chemical properties of silicon have shown to be extremely useful
in modern communication,
and because of its importance in pretty much all our electronic devices,
the name Silicon Valley makes a lot more sense now, doesn’t it?
And the best thing here is that silicon is the second most abundant element
in Earth’s crust.

These large crystals here are quartz; it’s a mineral containing silicon.

And sand, the same thing.
But silicon is not the only link between communication and chemistry.
The LCD screens we have on many electrical devices
are results of chemical innovations, as well as touch screens.
And get this, chemical researchers are now even coming up with ways to print
electronic displays onto paper.
Alright, thanks.
Well, that explains it.
But if you thought humans were the only ones using chemistry in communication,
you’re wrong. Check this out!
Chemical communication is widely used by other animals as well.
Ants, for example, lay out chemical scent trails for the other ants to follow
and find their way.
And many animals find a partner to mate with using special molecules, or pheromones,
that are detected by the other individuals.
And some animals even communicate using light produced through a chemical reaction
referred to as bioluminescence.

So, that’s it.
And since Louise is not here, all I have to say is…

Hey, I almost forgot!
Remember, Chemistry is all around You!