Diodes are electronic components that only let electricity flow in one direction in ideal conditions. An exception is a Zener diode, which does only allow electricity to flow in one direction until a voltage threshold is reached, and then it can pass through the diode. Diodes are useful for many electronic applications where electrical current may travel the wrong way through a circuit under certain conditions; in those situations, diodes can be used to prevent that and only allow current to flow in the correct directions.
How a Diode Works by Hana Shoib
Light Emitting Diodes
Commonly referred to as their acronym "LED", light emitting diodes are diode components in which light emission is a byproduct of the electricity passing through the diode element. They come in a variety of colors, and are much more energy efficient than incandescent light bulbs.
Light emitting diodes come in a variety of colors based on the materials they are made of, and actually emit that color of light instead of needing to be passed through a filter.
The Elusive Blue LED
Before 1993, LEDs had a major limitation. There were a number of colors available, including two of the three primary colors. However, without all three primary colors, white (without a noticable tint) could not be created. That missing color was blue, and its creation was vital to the lighting revolution that LEDs would bring to basically all forms of technology.
This video was uploaded to the LGR channel by Clint Basinger on Sep 29, 2017, as part of the Tech Tales series.