Question

How Can I Make A Diode?

Answer 1

PN junction diode:

1. A diode is a semiconducting device, that allows current to flow in one direction but not the other. A semiconductor is a kind of material, in this case, silicon or germanium, whose electrical properties lie between those of conductors (metals) and insulators (glass, rubber).
2. You can change the behavior of pure material, like silicon, and turn it into a semiconductor by doping. With N-type doping, phosphorus or arsenic is added, in parts per billion, to the silicon in small quantities.
3. It takes only a very small quantity of the impurity to create enough free electrons to allow an electric current to flow through the silicon. Electrons have a negative charge, hence the name N-type.
4. In P-type doping, boron or gallium is added to the pure silicon. Those elements each have three outer electrons. The absence of an electron creates the effect of a positive charge, hence the name P-type. Holes can conduct current.
5. A hole happily accepts an electron from a neighbor, moving the hole over a space.

Diodes are made from two differently doped layers of semiconductor material that form a PN junction. The P-type material has a surplus of positive charge carriers (holes) and the N-type, has a surplus of electrons.