The width of the forbidden gap in a silicon c | vedclass

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(C) In an intrinsic semiconductor,the Fermi level $E_i$ lies approximately in the middle of the forbidden energy gap,i.e.,$E_i \approx E_c - E_g/2$.Fo

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Lesser than $0.55 \, eV$

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(C) In an intrinsic semiconductor,the Fermi level $E_i$ lies approximately in the middle of the forbidden energy gap,i.e.,$E_i \approx E_c - E_g/2$.For an $N$-type semiconductor,the addition of donor impurities introduces donor energy levels just below the conduction band. This causes the Fermi level $E_f$ to shift upwards towards the conduction band.Since the Fermi level $E_f$ moves closer to the conduction band $E_c$,the energy difference $(E_c - E_f)$ becomes smaller than the energy difference in an intrinsic semiconductor.In an intrinsic semiconductor,the distance from the conduction band is $E_g/2 = 1.1 \, eV / 2 = 0.55 \, eV$.Therefore,for an $N$-type semiconductor,the distance of the Fermi level from the conduction band is less than $0.55 \, eV$.

The width of the forbidden gap in a silicon crystal is $1.1 \, eV$. When the crystal is converted into an $N$-type semiconductor,the distance of the Fermi level from the conduction band is:

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