ABSTRACT
This chapter discusses how some of the most common electronic devices work, what they tend to be made from, and how they are manufactured. It discusses insulating materials, which play an important role in semiconductor devices. When a p-n junction is made from one type of semiconductor, it can be doped with acceptor atoms on one side to make it p-type, and with donor atoms on the other side to make that side n-type. The diffusion that occurs when a p-n junction is first created does not continue until the concentrations are uniform, as the charge from the uncompensated ions in the depletion region creates a potential difference between the two sides. Tunnelling only occurs in p-n junctions with high levels of doping that have also had a reverse bias applied that is above a “critical value” that causes the top of the valence band on the p-side to lie above the bottom of the conduction band on the n-side.
