A selection of 5mm LEDs.
The LED on the left is a red/green bicolour LED.
The LED between the yellow and green is an infra-red LED.
A point contact Germanium diode - OA91.
Useful for rectifying radio signals because of its low forward voltage.
A close up of a LED.
Two examples of bridge rectifiers.
Useful for rectifying the output of a transformer.
A metal rectifier.
Note the fins to dissipate the heat generated.
Power diodes 1N5401 and 1N4001 with a 5V1 zener diode.