SEMICONDUCTOR DEVICE PHYSICS AND DESIGN

238 CHAPTER 5. SEMICONDUCTOR JUNCTIONS

Figure 5.12: Solutions to example 5.3

kBT

[

ln

(

p

NV

)

+A 1

p

NV

+A 2

(

p

NV

) 2 ]

=0.011 eV

The solutions are plotted in figure 5.12.

5.6.3 Quasi-electricfields ............................

In a homogeneous semiconductor, the separation between the conduction and valence bands is
everywhere equal to the semiconductor bandgap. Any electric field applied to the material there-
fore results in an equal slope in the conduction and valence bands, as indicated in figure 5.13a.
When a hole or electron is placed in this structure, a force of magnitudeeEwill act on the par-
ticle. The magnitude of the force is equal to the slope of the bands and is the same for both
electrons and holes. However, the direction of the force is opposite for the two particles.