Home
Class 12
PHYSICS
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.

Text Solution

Verified by Experts

(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.`
Promotional Banner

Similar Questions

Explore conceptually related problems

A doped semiconductor has impurity levels 40 me V below the conductor band. Is the material n-type or p-type? In a thermal collision, an 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. Given k=8.62xx10^(-5) eV//K .

A doped semiconductor has impurity levels 32 meV below the conduction band. The semiconductor is -

A doped semiconductor has impurity levels 20 meV below the conduction band. Is the material n-type or p-type? What is the wavelength of light so that the electron of impurity level is just able to jump into conduction band? Use h=6.63xx10^(-34)Js, c=3xx10^(8)m//s .

An n-type semiconductor has impurity level 20 meV below the conduction band. In a thermal collision, transferble enegry is KT . The value of T for which electrons start to jump in conduction bond is :

Impurity levels in a doped semiconductor is found to be 35 millielectron volts below the conduction at temperature T_(1) when thermal collisions take place approximate amount of energy and reach the conduction band due to collisions then estimate the temperature of the sample

in an n-type semiconductor, the donor energy level lies (a) at the center of the energy gap (b) just below the conduction band (c)just above the valence band (d) in the conduction band

When a semiconducting meterial is doped with an impurity,new acceptor levels are created .In a particular thermal collision,a valence electrons recives an energy equal to 2kT and just reaches one of the acceptor levels. Assuming that the energy of the electron was at the top edge of hte valence band and that the temperature T is equal to 300K, find the energy of the acceptor levels above the valence band.

When an electron goes fron the valence band to the conduction band in silicon,its energy is increased by 1.1eV.the average energy exchange in a thermal collision is of the order of kT which is only 0.026eV at room tempareture.How is a thermal collision able to take some of the electrons from the valence band to the conduction band ?