… you’ve may well have started seeing Christmas lights starting to appear adorning houses and Christmas trees. How do these lights actually work, and how can they be made to produce such an array of colours? This graphic takes a look at the chemistry.
The colours obtained from LEDs are determined by the semiconducting materials used. As you can see in the graphic, there’s not just one material used for all of the different colours, but a range of possibilities. By using different materials, and adding different impurities to these materials, we can change the size of the band gap – that is, the size of the energy difference between the n-type layer and the p-type layer. The bigger this band gap, the shorter the wavelength of light produced by the LED. So for a red LED, a relatively small band gap is required. For blue LEDs, a larger band gap is needed.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.