Light-emitting diode phosphors provide more diffuse light, which is desirable for many applications. Remote phosphor designs are also more tolerant of variations in the LED emissions spectrum. A common yellow phosphor material is cerium-doped yttrium aluminium garnet (Ce:YAG). White LEDs can also be made by coating near-ultraviolet (NUV) LEDs with a mixture of high-efficiency europium-based phosphors that emit red and blue, plus copper and aluminium-doped zinc sulfide (ZnS:Cu, Al) that emits green. This is a method analogous to the way fluorescent lamps work. This method is less efficient than blue LEDs with YAG:Ce phosphor, as the Stokes shift is larger, so more
LED tattoo irritation because they are nanometers thick. LED tattoos would not interfere with normal physiological processes. The U.S. Food and Drug Administration (FDA) have approved LED technology but LED tattoos are undergoing continual development. One such medical application would be silk-silicon LEDs to create photonic tattoos which would assist in blood-sugar readings. Perfected for clinical use and mass production, these devices could see patients sent home from the GP or from surgery with a monitoring system that does the job of several heavy-duty machines—like electromyographs, an EEG or electrocardiogram—normally confined to hospitals. LED tattoo A light-emitting diode tattoo is a type