HowStuffWorks: How Light Emitting Diodes Work Discover more about the physics and chemistry of LEDs in this step-by-step introduction. Nobelprize.org: Blue LEDs – Filling the world with new light ...

How does a varactor diode work? To form the PN junction that makes a diode, half the piece is doped with a trace amount of “donor atoms” that have one more electron than the intrinsic stuff to make ...