semiconductor as thermometer

[praveen450]

Hi,

I have n type doped semiconductor with conductivity at different temperatures from 0 to 550K.Now suppose I want to use this semiconductor as a thermometer at room temperature around 50K i.e from 250K to 350K.How can I know whether this semiconductor works as thermometer around this specified temperature depending on this conductivity values?.

 

[kalyanasv]

i) The best approach would be to run a SPICE simulation with the semiconductor parameters in the model file.

ii) If you already have it fabricated, then literally plug it like a variable resistance and check the output current.

iii) Given a the conductivity of the semiconductor and mobility etc..there are also simpler analytic model e.g. book by S.M.Sze on semiconductor devices has some closed form equations for temperature models.

 

[praveen450]

So,the conductivity should vary linearly with mobility inorder to work as a thermometer?.

 

[kalyanasv]

Not necessarily, as long as you can attach a suitable equation to it you should be fine. for e.g. if T=exp(-kρ) where ρ is the conductivity you should still be able to measure the temperature.
All you need is a functional mapping from your domain i.e. temperature which maps to its corresponding conductivity.