Semiconductor Electronics
Exercise No. 2
1. Give the electronic structure of potassium (Z=19).
2. What is the electronic configuration of Germanium with the atomic number of 32?
3. Find the 4 quantum numbers of iron(Fe) Z= 26.
4. Assume the Fermi energy is 0.25eV below the conduction band. The value of Nc for Silicon
at T= 300 K is Nc = 2.8 x 1019 cm-3. Calculate the probability that a state in the conduction
band is occupied by an electron and calculate the thermal equilibrium electron
concentration in silicon at T=300 K.
5. Assume that the Fermi energy is 0.27eV above the valence band energy. The value of Nv
for Silicon at T = 300K is Nv = 1.04 x 1019 cm-3. Calculate the thermal equilibrium hole
concentration in silicon at T = 400 K.
6. Calculate the intrinsic carrier concentration in Gallium Arsenide at T = 300 K and at T =
450K. The values of Nc and Nv at 300K for Gallium Arsenide are 4.7 x 1017 cm-3 and 7.0 x
1018 cm-3, respectively. Both Nc and Nv vary as T3/2. Assume the band gap energy of
Gallium Arsenide is 1.42eV and does not vary with temperature over this range. The value
of kT at 450 K is:
7. Consider an n-type Silicon semiconductor at T = 300K in which Nd = 1016 cm-1 and Na = 0.
The intrinsic carrier concentration is assumed to be ni = 1.5 x 1010 cm-3. Determine the
thermal equilibrium electron and hole concentrations for the given doping concentration.