In 1907, a British engineer Henry Joseph Laud working in English Electric Company observed the phenomenon of electroluminescence for the first time. Yellow light can be observed under low voltage and light with more colors can be observed under high voltage. This electroluminescence phenomenon has established the physical basis for LED to be invented.In 1962, a 34 year old normal researcher in GE in America invented LED that can emit red light, and since then his name Nick Holonyak is as red and popular as red light LED. The invention of Holonyak is later widely applied and he was named as “the father of light-emitting diode”. Standing on the shoulders of Holonyak, his student George Crawford invented the first orange light LED in 1972, which is ten times brighter than that of red light LED.By the time of late 1970s, LED Lighting already had colors of red, orange, yellow, green and jade green, but there were still no blue lightLED Lights . Three original colors are contained in light, including red, green and blue. The absence of blue light source has made white light source hardly accessible. The large market value of blue led high bay made it a technical problem at that time and many scientists have devoted to cracking this problem.