Views: 3 Author: Kina Publish Time: 2016-11-08 Origin: Site
① 1962, GE, Monsanto, IBM's joint laboratory developed a red phosphor phosphorus gallium arsenide (GaAsP) semiconductor compounds, from visible light-emitting diodes into the commercial development process.
In 1965, the world's first commercially available light-emitting diode, which is made of germanium materials can be issued by infrared light LED, then the unit price of about 45 US dollars. Shortly thereafter, Monsanto and Hewlett-Packard launched a commercially available red LED with GaAsP. The efficiency of this LED is about 0.1 lumens per watt, which is 100 times lower than the typical 60 to 100 watt incandescent lamp's 15 lumens per watt.
In 1968, LED research and development has made a breakthrough, the use of nitrogen-doped process GaAsP device efficiency reached 1 lumens / watt, and can issue red, orange and yellow light.
④1971, the industry has introduced the same efficiency GaP green chip LED.
⑤ to the 20th century, 70 years, due to LED devices in the home and office equipment in a large number of applications, LED prices plummeted. In fact, LED main market in that era of digital and text display technology applications.
A major technological breakthrough in the early 1980s was the development of the AlGaAsLED, which emits red light at a luminous efficiency of 10 lumens per watt. This technological advancement enables the LED to be used in outdoor information distribution as well as automotive high-level brake light (CHMSL) equipment.
⑦ In 1990, the industry has developed to provide the equivalent of the best performance of red devices AlInGaP technology, which was more than standard GaAsP device performance 10 times higher.
⑧ Today, the most efficient LED is made of transparent substrate AlInGaP material. Between 1991 and 2001, advances in materials technology, chip size and form factor led to a nearly 30-fold improvement in the flux of commercial LEDs.
⑨ 1994, the Japanese scientist Nakamura repair in the GaN substrate developed the first blue light-emitting diodes, which led to the GaN-based LED research and development boom. In 1996 by the Japanese company Nichia (Nichia) successfully developed a white LED.
⑩ 20th century, the late 90s, developed by the blue light excitation YAG phosphor produce white LED, but the color is not uniform, short life, high prices. With the continuous progress of technology in recent years, the rapid development of white LED, white LED luminous efficiency has reached 38lm / W, laboratory research results can reach 70lm / W, much more than incandescent, fluorescent approximation.
In recent years, with the continuous deepening of research on semiconductor luminescent materials, the continuous progress of LED manufacturing process and the development and application of new materials (nitride crystal and phosphor), super bright LED of various colors has achieved breakthrough Development, and its luminous efficiency increased by nearly 1000 times, color has been achieved in the visible band of all colors, the most important of which is the emergence of ultra-high brightness white LED, LED applications across the market to high efficiency lighting source possible. It has been pointed out that high-brightness LED will be the human following Edison invented incandescent bulbs, the greatest one of the invention.