Problemsamling

(b) What is the corresponding factor for a simple cubic lattice in three
dimensions?
(c) What is implied by the fact that the Brillouin zone can be associated
with different energies?
10. The Fermi energy of copper at 0 K is 7 eV. Calculate the mean energy of
the conduction electrons and their root mean square velocity.
11 Calculate the electronic specific heat of a mole of copper at 300 K. At what
low temperature are the electronic and lattice specific heats of copper equal
to one another?
12. The Hall coefficient of Al is 1.02 10 -10 Vm/AT. How many electrons per
atom take part in electrical conduction?
Semiconductors (Se)
1. Calculate the position of the intrinsic Fermi level in InP at room
temperature when the bandgap is Eg = 1.26 eV. Where does the Fermi
level lie at T = 0 K if Eg is assumed to be temperature independent?
(me = 0.073 m and mh = 0.2 m.)
2. A measurement of the voltage drop U across an InSb sample was made as a
function of temperature, T, with a constant current to determine its
bandgap and the measured values below were obtained. The whole time,
the sample was in the temperature interval for intrinsic conduction.
T [K] 237.7 245.5 255.5 268.1 275.7 283.7 290.6
U [mV] 6.817 5.862 4.821 3.827 3.358 2.910 2.610
4