pn junctions?

[LazyZombie]

So my teacher went on for a while about pn junctions and diodes and stuff for awhile, and I didn't understand much of it at all ><

And then she finished by saying, don't worry, you don't really need to know about pn junctions.

Is it a good idea to understand how they work and what they are?

[kaiipoo_]

only a basic knowledge of pn junctions is needed for the scope of the course, unless you're doing further electronics or photonics as a detailed study. I find although its not necessary, it helps in understanding how photodiodes, phototransistors, LED'S and LDR'S work.

My schools doing materials and structures so it's not needed.

Basically, a p-n junction is made by joining an 'n type' and a 'p type'. These 'types' are achieved by doping, which is basically replacing on of the atoms in a lattice with another. eg. Replacing a Silicon atom in a Silicon Diode with a Phosphorus atom. A Phosphorus atom has one more electron than a silicon atom, thus forming an 'n type' (excess electrons). p types are made using a similar process, except with say, Aluminium atoms.