The Diodes

A large variety of diodes are commercially available. In these experiments, you focus on so-called rectifier diodes.

Basically, there are two versions of rectifier diodes...

Diodes with a semiconductor-semiconductor junction (silicon diode, germanium diode...),
Diodes with a metal-semiconductor junction (Schottky diode).

They have in common that they have two ports, the anode (A) and cathode (K). The cathode is typically marked by a printed ring.

In the experiments, you use three different rectifier diodes...

1N4001, 1N914 (Silicon diodes)
BAT43 (Schottky diode)

Several diodes. (Enlarge)

There are other diodes, which are closely related to rectifier diodes... light-emitting diodes (LEDs), Zener diodes and photodiodes. They are not discussed here, but in separate topics.