March 2014
Intermediate to advanced
624 pages
26h 33m
English
4.1 With EF located 0.4 eV above the valence band in a Si sample, what charge state would you expect for most Ga atoms in the sample? What would be the predominant charge state of Zn? Au? Note: By charge state we mean neutral, singly positive, doubly negative, etc.
4.2 A Si sample with 1016/cm3 donors is optically excited such that 1019/cm3 EHPs are generated per second uniformly in the sample. The laser causes the sample to heat up to 450 K. Find the quasi-Fermi levels and the change in conductivity of the sample upon shining the light. Electron and hole lifetimes are both 10 µs. Dp = 12 cm2/s; Dn = 36 cm2/s; ni = 1014 cm–3 at 450 K. What is the change in conductivity upon shining light?
4.3 Construct a semilogarithmic plot such ...