In the 1960s, scientists and technicians developed LED light-emitting diodes using the principle of semiconductor PN junction light. The LED used at that time was made of GaASP, and its luminescent color was red. After nearly 30 years of development, LEDs that are very familiar to everyone have been able to emit red, orange, yellow, green, blue and other colors. However, the white LEDs required for lighting were only developed after 2000. Here, readers will be introduced with white LEDs for lighting.