BE Civil Engineering Semester 1 (FE First Year)University of Mumbai
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# In a solid the energy level is lying 0.012 eV below Fermi level. What is the probability of this level not being occupied by an electron 27℃? - BE Civil Engineering Semester 1 (FE First Year) - Applied Physics 1

ConceptFermi Energy Level in Intrinsic Semiconductors

#### Question

In a solid the energy level is lying 0.012 eV below Fermi level. What is the probability of this level not being occupied by an electron 27℃?

#### Solution

:-Data  :- -EF E=0.012eV  ,T=27℃=300K

K=1.38×10^(-23) J/K= =(1.38×10^(-23))/(1.6×10^(-19 ))=86.25×10^-6  eV/K

Formula :-f(Ec)=  1/(1+e("^(E_c- E_F))/(kT )
Calculations:-Total probability = 1

Probability of occupying an energy state + Probability of not occupying the energy state = 1. f(E) + Probability of not occupying the energy state = 1 Probability of not occupying the energy state = 1- f(E)

"Here" f(E) =1/(1+e((E-E_f))/(kT )) =1/(1+e^((0.012/86.25×10^-6×300))) = 0.386

Hence ,1-f(E)=1-0.386=0.614