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A doped semiconductor has impurity level...

A doped semiconductor has impurity levels 30meV bleow the conduction band,(a)Is the material m-type or p-type? (b)In a thermal collision,and amount kT of energy is given to the extra electron loosely bound to the impurity ion and this electron is just able to jump into the conduction band. Calculate the temperature T.

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The separation of impurity energy level from conduction band is less in case of n-type semiconductor and more in case of p-type semiconductor. As energy separation of impurity level `=30xx10^(-3)eV` is much smaller than energy gap of pure semiconductor `(~~1eV)`, therefore, the doped semiconductor is n-type.
Here, `E_(g)=30xx10^(-3)eV=kT`
or `T=(30xx10^(-3))/k=(30xx10^(-3))/(8.62xx10^(-5))=348K`
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