1. B.G.Streetman: 3.15, p. 94. For this problem, assume that the Fermi-Dirac
occupation function is valid for dopants.
(note: actually, it needs to be modified slightly).
2. B.G.Streetman: 3.16, p.94.
3. B.G.Streetman: 3.17, p. 94.
4. B.G.Streetman: 4.1, p. 126.
5. B.G.Streetman: 4.5, p. 126.
6. B.G.Streetman: 4.7, p. 126.
7. B.G.Streetman: 4.8, p. 127.