Appendix G. More on Semiconductors
P-N junctions, depletion zones, and diodes
Do you recall way back in the mists of time [known as Chapter 4: Semiconductors (Diodes and Transistors)] when we first introduced the concept of a semiconductor diode? This was formed by doping a piece of silicon such that one part was P-type and the other was N-type (Figure G.1). As we discussed, the resulting p-n junction conducts electricity in only one direction: in the other direction it behaves like an OPEN (OFF) switch.
Figure G-1. Creating a diode from P-type and N-type silicon.
However, we sort of “glossed over” the way in which this actually works, so let’s ...