The world's first full color gallium nitride based LED
The Ostendo EpiLab laboratory in southern California has developed the world's first RGB LED. The LED is based on GaN technology. It uses three specific materials to form quantum structures, which can emit different colors of light. Color LED can separate or emit light separately. The traditional LED is usually monochromatic and can only transmit a single wavelength. To achieve a colorful RGB lighting effect, you need to use multiple LED to mix the required colors.
The color is determined by the phosphor coating or base material of LED. Only a few researchers have tried to create a single LED chip that can launch a full range of RGB colors.
GaN makes green light LED brighter
An electronic and Computer Engineering Scientist at the University of Illinois, Urbana-Champaign has developed a new way to make a brighter, more efficient green LED. An industry standard semiconductor growth method is used to grow gallium nitride (GaN) cubic crystals on a silicon substrate to produce strong green light for solid state lighting.
Usually, GaN forms one of two crystal structures: six square crystals or cubic crystals. The six square GaN is thermodynamically stable and is the conventional form used in semiconductor applications. However, the six party GaN is more prone to polarization. The internal electric field separates the negative electrons from the positron and prevents them from binding, thereby reducing the efficiency of light output.
Use new materials to make efficient white light LED
Researchers at National Tsinghua University recently published a paper in science magazine ACS Nano, which successfully made use of new materials instead of rare earth metals to make white LED products. The LED is basically made of alkali strontium, combined with metal organic framework (MOF), and white light LED is made by combining graphene and other materials on the upper and lower layers of MOF. The LED made from the new material can produce a beam of similar quality to the natural light, and does not produce a strong blue light. The efficiency of the lumen is significantly improved because it does not have to filter out other colors.
The Japanese R & D of red LED with no rare elements
Tokyo Institutet of Technology and Kyoto University have jointly announced that red light-emitting semiconductors that do not use expensive and rare elements have been developed.
Researchers are turning to the use of rich elements on the earth as alternatives, such as the use of nitrogen and zinc as a criterion for screening. Low cost materials can reduce the cost of the production of red LED and solar cells.
Reduction of LED inhibition efficiency in hybrid nanocrystalline
Researchers at the Nanjing University have discovered a new application of hybrid nano crystal, can be used for filling InGaN or GaN LED structural holes, to significantly improve the luminous efficiency of white LED.
The study was published in the "Applied Physics Letters", points out that improving the color conversion efficiency (CCE) is the key to the effective non radiative resonance energy transfer decision, rather than with the blue InGaN/GaN LED, or down conversion material (such as phosphorus or even semiconductor nanocrystals).
Progress of UV LED free surface light matching technology
The important progress made in the application of Chinese Academy of Sciences Chongqing Green Intelligent Technology Research Institute for integrated optoelectronic technology research center in the ultraviolet LED free surface light distribution technology, the success of LED ultraviolet light source for exposure machine, products have been in the PCB, LCD panel, touch screen industry was used. The traditional parallel light exposure machine uses high pressure mercury lamp as the light source, its life is only 1000 hours, the power consumption is high, and it is polluted. Using UVLED to replace the mercury lamp light source, the life span can reach 50 times of the mercury lamp, the power consumption can be reduced by 90%, the production cost of the enterprise is greatly reduced, and the environmental protection is no pollution.
At present, the Chongqing academy has breakthrough the key technology of LED multi precision optical free-form surface, suitable for ultraviolet inorganic optical element processing, first developed a parallel light ultraviolet exposure head based on LED, the parallel angle can be controlled within about 2 degrees, lighting uniformity is less than 3%, lighting intensity reached 40mW/cm2.
New breakthrough of LED heat dissipation device
Li Kuanan, senior engineer of the China Light Industry Federation, introduced an innovative LED heat dissipation technology with independent intellectual property rights. These companies can successfully eliminate all obstacles and use wire form and fan force to heat the heat and get good heat dissipation. Inventor Zhang Yixing pointed out that the design solves the heat dissipation problem and meets the demand of LED driving power supply with high efficiency, high reliability and low cost, which fundamentally solves the two major problems of LED development.
The new material provides longer life expectancy for white LED
Xiang Weidong, a professor of chemistry and material engineering at the Wenzhou University, invented the innovative material that extended the life of LED lamps for nearly 10 years. Long time lighting makes this material more widely used in luxury cars, high speed railways, aircraft, subway and other lighting applications.
Weidong spent many years in a high temperature of 2000 DEG C under single LED chip synthesis on the Yellow light. If a blue light LED chip is paired with a 5.5mm * 5.5mm 24W source on a single chip, the yellow crystal material can produce a stable white light. Because of the heat resistance and high conductivity of the chip, the elasticity of LED lamps will be greater and the life span is longer. The LED light bulb is not easily damaged by high temperature after long time lighting. It is very suitable for the lighting applications of luxury cars, car lights, high speed railways, aircraft and submarines.
Mercedes launched an independent LED headlight
Mercedes Benz introduces a multi beam LED headlight with 84 LED light sources to achieve higher optical output resolution. This allows other road users to better prevent glare and improve the road lighting in front of the driver.
Because the light distribution is completely free, we can realize all the high beam and low beam functions of the intelligent lighting system for the first time in full digital mode without any mechanical actuators. This will make a large number of new adaptive lighting functions possible, which will make the night driving safer.
This technology is developing rapidly: soon, there are 1024 separate pixels on each LED chip, which will further improve night visibility and further improve safety. Infineon, OSRAM, Fraunhofer Gesellschaft IZM, Hella and Daimler and other partners have made breakthroughs in the "Mu AFS" research project. The new LED chip has very fine structure. The monolithically structured pixel LED semiconductor layer is built on silicon substrate. Through the integrated circuit, each LED chip allows selective control of 1024 individually addressable pixels.