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.

Explanation

(a) The impurity provides impurity levels close to the conduction band and a number of electrons form the impurity level will populate the conduction band. Thus,the majority carriers are electrons and the meterial is n-type.
9According to the question,`kT=30meV`
or,`T=(30meV)/(k)`
`=0.03eV/8.62xx10^(-5)eVK_(-1)=348K.`