Diodes

You know what made me really happy today? Explaining how Diodes work. Diodes are such fun and miracle stuff, they are so cheap and easily accessible now, and the function is simple, people rarely appreciate the extraordinary human intellectual anymore-

For semiconductor diodes, and all semiconductor materials, there exist a structure called PN junction (it’s uniquely semiconductor property, that’s why it’s different or say, make it a semiconductor), electrons go from one side to the other, P to N or N to P. Between the two regions there’s a thing called depletion region, which is like an empty ground, or the middle of a football pitch. For a diode, if you make the ‘right’ direction of the current, the electrons can flow through and run across the fields, if you make the ‘wrong’ direction it will make the depletion region even larger.

That’s how diodes filter and only allow one direction of current- hence make yes/no (0/1) gates.

It sounds incredibly easy. I think the beauty is to realize things like this actually happens in an ordinary rock(the PN junction. PN junction can also give you light or electrons, hence to make light bulb laser and solar cell), and make nano sized lil diodes with it so we can have what we have now.