AlGaN-Based Ultraviolet Light Emitting Diode

The brillian spot on the right side is the body of the ultraviolet Light Emitting Diode (UV-LED). Blue halo on the left side in an ordinary name card is the fluorescence excited by the dominant 346 nm emission. The halo is more bluish than the spot, because it is not a simple reflection of visible light from the UV-LED but a fluorescence.