Solid State Electronic Devices, 7th Edition

Problems

1. 4.1 With E_F 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.

2. 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 µ_s. D_p = 12 cm²/s; D_n = 36 cm²/s; n_i = 10¹⁴ cm^–3 at 450 K. What is the change in conductivity upon shining light?

3. 4.3 Construct a semilogarithmic plot such ...