# Model of intrinsic semiconductor behaviour

1. Jan 1, 2009

### jclough

1. The problem statement, all variables and given/known data
This isn't a problem as such. This is about a practical I did, to verify the non-classical model of silicon conductivity (which increases with temperature) and then to calculate the band gap energy of silicon.

2. Relevant equations
This was the main equation of the model we were verifying...
R=Ro*exp(To/T)

where To=Eg/2kB

kB = Boltzmann constant
Eg = band gap energy

Of course this only works in the intrinsic region.

I'm trying to think of other physical interpretations of the data for a certain section of the report and I was wondering if anybody knew where I could find a better model of semiconductor conductivity, perhaps a book or a website. That is, if there is a better model. I don't know if the model is the accepted one, as I haven't been taught about the topic!

Thanks,
Jessica.

2. Jan 24, 2009

### snapback

hello, hope it is not too late for your practical

you could consider following formula for the conductivity $\sigma$:

$\sigma=q\cdot \mu \cdot n$

with
• $q:$ electric charge
• $\mu:$ mobility
• $n:$ free carrier concentration

the free carrier concetration depends mainly exponentially on temperature (there are some minor deviations, which are usually neglected). The mobility of carriers usually decreases with increasing temperature in an intrinsic semiconductor , thus the Ro in the equation you have been given, isn't actually constant

I do not know your background, but I think virtually any general book on semiconductor physics or physics of semiconductor devices could help you further. A very nice link is

http://www.tf.uni-kiel.de/matwis/amat/semi_en/index.html" [Broken]

good luck

Last edited by a moderator: May 3, 2017