History of led

In 1961, the U.S. company Texas Instruments Robert Biard and Gary Pittman was first discovered by gallium arsenide and other semiconductor alloys infrared radiation effects. In 1962, General Electric Company's Nick Ho Lun Yake (Nick Holonyak Jr.) Developed the first practical application may be visible light emitting diodes.

In 1993, Japan's Nichia (Nichia Corporation) work Shuji Nakamura (Shuji Nakamura) successfully infiltrated the nitrogen, creating a wide band gap semiconductor materials based on gallium nitride and indium gallium nitride (InGaN), with commercial applications The blue light emitting diode.

With blue light emitting diodes, the white light emitting diode conduction also immediately available, then they move towards increasing the luminosity LED direction, then the general power LED work are less than 30 to 60mW (milliwatts). 1999 input power up to 1W (watt) light-emitting diodes commercialized. In these light-emitting diodes are semiconductor chip to handle large high-power-on the problem, and the semiconductor chips are to be fixed to the metal sheet, to facilitate heat dissipation.

In 2002, the market began to have the appearance of a light emitting diode 5W, and its efficiency is about lumens per W 18-22lm.

September 2003, Cree, Inc. Demonstrated its new blue light-emitting diodes, the efficiency of 35% under 20mW. They also created an up to 65lm / W (lumens per watt) of white light emitting diode products, which was the brightest on the market white light emitting diodes.

2005 they demonstrated a prototype of white light emitting diodes in under 350mW, setting a record of 70 lm per watt of efficiency.

February 2009, the Japanese light-emitting diode maker Nichia Chemical (Nichia) published the efficiency up to 249 lm / W light-emitting diodes.

February 2010, Philips Lumileds made a white LED in a controlled laboratory environment, using a standard test conditions and driven to 350mA current draw 208lm / W, but because the company was not revealed a bias voltage, are not can learn about its power.

April 2012, the U.S. light-emitting diode maker Cree (Cree) launched 254 lm / W luminous efficiency again to refresh the power.

Compared to the general efficiency of the OLED light emitting diode is much lower, the highest are only about 10%. However, much lower production costs of OLED, for example, a simple printing method for the large-screen OLED array is placed on, for the manufacture of color display.