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lam58
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The question asks for a pn junction, calculate the total bending through energy at zero bias of the conduction band edge passing from neutral n-type section to the neutral p-type section.
Additional info:
Band gap of silicon Eg = 1.1 eV
Density of states at conduction band (Nc) = 2.8e19 states/cm^3
Density of states at valence band (Nv) = 1e19 states/cm^3
p-type contains 5e16 holes/cm^3 (p)
n-type contains 1e19 electrons/cm^3 (n)
Boltz constant k = 8.614e-5 eV/K
temperature = 300K
My ans:
qV_bi = Eb - ∂1 - ∂2, where ∂1 = (Ef-Ev) and ∂2 = (Ec-Ef)
if holes p = Nv*exp[-(Ef-Ev)/KT] = Nv*exp[-∂1/KT]
and electrons n = Nc*exp[-(Ec-Ef)/KT] = Nc*exp[-∂2/KT]
then ∂1 = KT*ln[Nv/p]
and ∂2 = KT*ln[Nc/n]
therefore qV_bi = EG - {KT*ln[Nv/p]} - {KT*ln[Nc/n]} = 0.62V
Is this correct?
Additional info:
Band gap of silicon Eg = 1.1 eV
Density of states at conduction band (Nc) = 2.8e19 states/cm^3
Density of states at valence band (Nv) = 1e19 states/cm^3
p-type contains 5e16 holes/cm^3 (p)
n-type contains 1e19 electrons/cm^3 (n)
Boltz constant k = 8.614e-5 eV/K
temperature = 300K
My ans:
qV_bi = Eb - ∂1 - ∂2, where ∂1 = (Ef-Ev) and ∂2 = (Ec-Ef)
if holes p = Nv*exp[-(Ef-Ev)/KT] = Nv*exp[-∂1/KT]
and electrons n = Nc*exp[-(Ec-Ef)/KT] = Nc*exp[-∂2/KT]
then ∂1 = KT*ln[Nv/p]
and ∂2 = KT*ln[Nc/n]
therefore qV_bi = EG - {KT*ln[Nv/p]} - {KT*ln[Nc/n]} = 0.62V
Is this correct?
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