1. Chapter6. Carrier Transport

5. 6. 1 Drift 6.1.1 Definition-visualization Drift : Charged particle motion in response to an applied electric field. Visualization of carrier drift Figure 6.1 Visualization of carrier drift: (a) motion of carriers within a biased semiconductor bar; (b) drifting hole on a microscopic or atomic scale; (c) carrier drift on a macroscopic scale.

6. 6.1.2 Drift current Figure 6.2 Expanded view of a biased p-type semiconductor bar of cross- sectional area A

7. Relation between drift velocity and applied electric field

8. Figure 6.3 Measured drift velocity of carriers in high-purity Si and GaAs as a function of the applied electric field. Plots were constructed form 300data presented in ref.

19. Figure 6.7 Schematic drawing of the probe arrangement, placement, and biasing in the four-point probe measurement.

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22. 6. 2 Diffusion 6.2.1 Definition-visualization Figure 6.8 (a) Idealized visualization of particle diffusion on a microscopic scale. (b) Visualization of electron and hole diffusion on a microscopic scale.

23. 23/37 6.2.2 Diffusion current Figure 6.9 (a) p-type semiconductor bar of cross-sectional area A and (b) steady-state hole concentration about x = 0 envisioned in deriving the hole current associated with diffusion.

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27. 6.2.3 Einstein relationship Figure 6.10 Nonuniformly doped semiconductor under equilibrium conditions. (a) assumed doping variation with position; (b) corresponding equilibrium energy band diagram.

29. 6.3 Equations of state 6.3.1 Current equations

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31. Figure 6.11 Sample use of quasi-Fermi levels. Energy band description of the situation inside the text-described Si sample under (a) equilibrium conditions and (b) nonequilibrium conditions.

47. 6.3.2 Continuity equations

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