Review of the development process of LED light efficiency

LED has been developing for decades, but it is still a new technology in the field of lighting. With the rapid development of LED technology, its light-emitting efficiency gradually improve, LED application market will become even more widely, particularly in the global energy shortage fears rise again in the background, LED lighting market prospects in the global attention. Faced with the huge market opportunities, the world's major companies have accelerated the pace of R & D innovation. High power white LED in the laboratory has reached the level of 157 lm/w, close to 100lm/w high-power white LED is about to enter the commercialization. High power, high efficiency, low cost three bottlenecks are being gradually broken. It can be said that the dawn of white LED into the field of general lighting has emerged.

Here we publish the 100lm/W light effect in June 2006 Nichia white LED is a milepost in recent years, the luminous efficiency of LED development process of a simple comb.

(October 2008) CREE released a white LED light effect of up to 157lm/W

Cree company held a seminar in Switzerland announced its white light LED laboratory level has reached 157lm/W, its 102 lm/W products will be mass production.

(July 2008) Toshiba will be listed on the luminous flux 90lm white LED

Toshiba (USA) electronic components company mass production listed on the input current of 250mA, the beam is 90lm white LED "TL12W02-D". The new LED consists of 2 input current 250mA bundles of time for 40lm's LED chip package. When the input current is 250mA, the temperature is 25 DEG C can be obtained in the CIE chromaticity coordinates (x = 0.32, y = 0.31) of white light. By using the low thermal resistance package, the heat dissipation performance is improved. The working temperature range of -40 to + 100 DEG C, high temperature can reach a maximum of 110 degrees. When the forward current is 250mA, the forward voltage is 6.8V. The maximum power consumption is 2.4W. Surface mounting style of 10.5mm x 5.0mm x 2.1mm. Vision will be applied to industrial equipment and civil equipment. The price is $2.9 for each 10 thousand bulk purchase.

(May 2008) JLEDS modify the general lighting with white LED development blueprint

Japan LED lighting Promotion Association (JLEDS) discloses a lighting apparatus with high power LED technology development blueprint, put forward respectively white ordinary products (high efficiency type), high color products and lighting color products (lamp color type) by the end of 2020 the luminous efficiency targets. According to the target, before and after 2015 luminous efficiency is expected to reach 150lm/W. In general, the luminous efficiency of high efficiency products in fluorescent lamp is about 100lm/W, the efficiency of white LED products in 2008 will reach about 100lm/W, high color type will be more than 80lm/W, the bulb color type will reach about 70lm/W. 2010 is expected to reach about 130lm/W, 120lm/W and above 90lm/W, in 2015 is expected to reach more than 160lm/W, 140lm/W and above 130lm/W. With regard to the popularity of LED lighting, the technology development blueprint, said the luminous efficiency of more than 100lm/W in 2010 around the commercial facilities as the center for universal. In the light (white light emitted from the LED light toning etc.) improved after 2015, LED lighting will be popularized in the office and residential areas.

The technology development program also addresses the challenges of promoting universal access. It is pointed out that the biggest subject of popularization is cost. The cost of LED lighting fixtures is 5 to 10 times that of fluorescent lamps and HID appliances. This is because the price of the unit brightness of the light source (yen /lm), the white LED to be higher than two digits, but also the need for heat sink, power and lenses, etc.. JLEDS believes that not only to reduce the cost of light source, reduce the cost of peripheral components is also very important. In addition, attaches great importance to indoor lighting color temperature and color rendering, so it is also necessary to improve the quality.

(September 2007) Nichia released 350mA time effect 134lm/W high power white LED

Nichia released the location for the 1W LED the next generation of high power white LED. 350mA current input flux of 145lm, luminous efficiency of 134lm/W. The efficiency of the light output corresponding to the input energy is 39.5%. The product for the YAG phosphor and blue LED chipset and variety, chip size of 1mm square. Intended for general lighting applications, color temperature is 4988K, close to the general lighting 5000K. For the convenience of measurement, pulse current input is also used. Specific production time undetermined.

The reason for the realization of the white LED high efficiency is achieved by the use of blue LED chip efficiency. The blue LED in the 350mA drive when the optical power is 651m/W, the wavelength of 444nm. The external quantum efficiency is 66.5% and WPE is about 60.3%. 1A driver, optical power up to 1.7W. The release of the next generation of products for the higher forward voltage. In the future, the epitaxial growth method will be optimized to reduce the forward voltage.

(September 2007) CITIZEN electronics developed 540lm lighting with white LED

CITIZEN electronics has developed a white LED "CL-L102-C7" series that can be used to achieve 540lm luminous flux when the 700mA current is input. Plans to supply samples from October 2007, January 2008 production supply. The development of white LED is the company's sales of the "CL-L102-C3" series (input 350mA current time flux of 245lm) high power products. New product luminous efficiency is higher, the input 700mA current is 74lm/W, the input 350mA current is 90lm/W. The LED in the light of 150lm, the input current can be reduced by 160mA, luminous efficiency can be greatly improved by 110lm/W. The new product's size is 50mm * 7mm * 2mm. Color temperature is 5000K, the future will launch 2900K varieties.

(August 2007) OSRAM released the red and orange 85lm/W LED

Germany OSRAM