!--> Doping Help Please<--! (1 Viewer)

[BlackDragon]

Hello everyone!
I've got a question...i know that p and n-type doing both, in essence, raise the conductivity of semi conductors, but why aren't ordinary conductors used instead of making the semi conductors conduct more freely? especially in solid state devices (computer chips basically) because i know why they need to be used in photo voltaic cells. so yeah, what is the purpose of semi conductors and doping them over normal conductors generally, and if you can answer in solid state devices.
thanks everyone, i appreciate it.

 

[zeek]

thats a really good question which i havent actually thought about lol. the best reason i can think of is that when thermionic devices were phased out and solid state devices were implemented, engineers needed a way to manipulate currents. Manipulating currents would generate large amounts of heat when more and more components were used and if a metallic conductor were to be used, then the resistance would increase (as resistance is proportional to temperature). This would result in a reduced current flowing through a circuit which could lead to various effects e.g. singal loss.
When using semiconductors, the temperature would also increase, but because of the nature of semiconductors, as the temperature increases the resistance levels decrease (since the amount of energy required to jump energy gaps is readily supplied by the increased temperature). This would allow for the same amount of current to flow through without affecting the flow.

 

[BlackDragon]

can anyone confirm that or tell me something different?
because i have this assessment question and i'm yet to find out why we need doping. and how they have helped in the development of solid state circuits.
here's the question if it helps.

' "Doping has played a very important part in the development of solid state circuits and as a result has contributed much to the 'Computer Age', which is also known as the age of communication" Discuss this statement fully explaining clearly what is meant by doping, solid state physics, the computer age and any other relevent ideas. '

by the way, thanks for your help revenge.

p.s. can anyone point me to a website that explains this particular query? its very important.

 

[zeek]

Well the only reason people switched over to solid state was because of the advantages they had which can be found here... http://en.wikipedia.org/wiki/Transistor#Advantages_of_transistors_over_vacuum_tubes
(it's for transistors but some can apply for most of the electronic components)

here's some information about doping - http://en.wikipedia.org/wiki/Doping_(semiconductors)

here's some stuff on semiconductors - http://electronics.howstuffworks.com/diode.htm
http://en.wikipedia.org/wiki/Semiconductors

 

[passion89]

Hmm that's a good question - why dope semiconductors instead of using normal conductors? I asked my teacher the exact same question...she mumbled something and made up some other stuff...in other words she had no idea and she had no answer.
But if anyone knows, that would be awesome.

Revenge's theory seems to make sense

 

[Jase]

semiconductors are not used 'in place' of conductors.

you could not make a diode or a transistor with a bunch of conductors. the whole point of doping semiconductors is to give them electrical properties (holes and electrons) which allow solid state devices to be made (placing N-types and P-types together). Solid state devices like the diode and transistor are the whole basis of electronics. conductors merely conduct..

 

[del pietro]

yep revenge and jase sound right..

semiconductors are used to create solid state devises which allow controlled direction and size of current such as the transistor and diodes..

as conductors heat up their resistivity increase, hence are no tsuitable to be used in integrated circuits.. semiconductors however decrease in resistivity as their temperature increases, allowing more uneffected motion of current and successful operation of the electronic device.. this has been summed up by revenge..