Seven of the "new materials" about LED technology, which one do you like?

LED semiconductor lighting Reuters someone says, "according to market demand, and constantly develop new products and actively explore the industry, product innovation using the market to find a breakthrough, and technical reserves in advance to lead the industry cutting-edge technology, to be invincible." . In this regard, Xiao Bian first deeply agrees that enterprises and units that can have such awareness and put into action will not be able to do anything big. And this truth, naturally, is universally applicable, including the LED industry.

Nowadays, there are fewer and fewer rare earth elements in the production of LED raw materials. It has been put on the agenda to develop a new LED that avoids rare earth elements. Osram is reported to be planning to use funds for LED wafer factories. Switched to iris scanning technology such as IRLED; Kyocera and high-end furniture brand Arflex Japan jointly developed lighting fixtures that use LED light sources with wavelength characteristics close to sunlight; Sony demonstrated its CLEDIS screen technology, which is described as a new technology that can challenge OLED;

Podium Aerospace's Podium Aerospace Division recently announced details of a reflective material sensor (RMS) system that uses light reflectance to detect ice accumulation; it is reported that Apple will first acquire a mature Micro- in the second half of 2017. LED display ; Saphlux has developed a new technology that can directly grow semi-polar gallium nitride on standard large-size sapphire substrates, solving the mass production problem.

Xiaobian today brought you a lot of new and exciting information related to LED technology .

1. New materials for white LEDs greatly improve luminous efficiency

LED products are gradually gaining popularity, but rare earth elements in the raw materials for making LEDs are becoming less and less. In order to solve this problem, some scholars have begun to study a new type of LED made by avoiding rare earth elements, such as using graphene to rewrite the current white LED technology . The current white LED, also known as white light diode, its white light is mainly realized by single crystal and polycrystalline. However, neither of these processes can avoid the use of rare earth elements. Among them, the former is composed of a single blue LED and a yellow phosphor on its surface, and the combination of the yellow light of the phosphor and the blue LED produces white light. The latter is packaged by LEDs of different colors, showing white light in complementary colors.

Recently, Taiwanese researchers have pointed out that the use of materials other than rare earth elements can also produce LED products that can emit white light. This LED is based on an alkali metal ruthenium, and a metal organic framework (MOF) is built. Graphene and other materials are combined on the upper and lower sides of the MOF to form an LED that can directly emit white light. MOF is formed by the combination of metal ions and organic materials. It has been widely used in the fields of chemical separators, drug delivery, gas storage, and catalysis for the past 20 years. However, because MOF is generally porous and has poor conductivity, it has not been used in the field of optoelectronics. On the periphery of the MOF material, the researchers also combined graphene, silicon dioxide, and zinc oxide to make them electrically lightable. It can be said that the use of MOF materials to manufacture light-emitting devices has given people a new idea.

2, Osram or the huge investment in IR LED and other iris scanning technology

According to industry insiders, Osram plans to transfer funds originally used for LED chip factories to IR scanning technologies such as IRLED. Depending on the size of the demand for iris identification products such as IR LEDs, depending on the smart phone manufacturer and the virtual reality system. Although the news has not yet been finalized, it is reported that OSRAM plans to invest at least 100 million euros (about 750 million yuan) to the LED wafer factory in Regensburg, Germany. It is hard to say, but the OSRAM official still does not comment.

Samsung, a South Korean company, is one of the manufacturers that uses iris recognition technology on smart phones. It has recently been the global recall of the Galaxy Note7 due to battery problems. At the same time, rumors that Apple plans to introduce similar features on future iPhones are also rampant. OSRAM has shifted its funds from LED semiconductor plants in Malaysia to other applications, and this move can be seen as a concession to investors who strongly oppose OSRAM LED wafer fabs in 2015. According to the German business report (Germandaily Handelsblatt), OSRAM will use the funds to set up factories in Regensburg, Germany and Wuxi, China.

3, the use of purple LED to achieve research and development of high-quality lighting

Kyocera and the high-end furniture brand Arflex Japan jointly developed lighting fixtures that use LED light sources with wavelength characteristics close to sunlight. This is a diffuse luminaire that can be placed on the floor like a piece of furniture to illuminate the ceiling, with a brightness equivalent to 150W of a halogen bulb. The light source used is based on a purple LED, and a fluorescent material that emits three primary colors is used in combination. Like sunlight, it emits light from a wide range of wavelengths from purple to red. Even white of the same color temperature is closer to sunlight than the light of the conventional ordinary LED light source. At present, lighting fixtures that use purple LEDs as light sources have been adopted by art galleries, museums, and some customers' homes that value space quality. However, since they consume more electricity than blue LED-based lighting fixtures, they have never been It can be used as a general lighting fixture for productization.

However, ArflexJapan has always believed that the era of purple LEDs will definitely be ushered in the future, not blue LEDs. In order to achieve productization, it has cooperated with Kyocera, a lighting artist who has experience in lighting design using a purple LED light source, to produce a purple LED. In order to improve heat dissipation, an air cooling mechanism is provided. That is, a vent hole is provided in a part of the lighting fixture, and the airflow flowing from the lower side of the lighting fixture to the upper portion is generated by convection. The life reduction caused by heat generation is suppressed, and the life of the light source is up to 100,000 hours. The development of LEDs and heat dissipation mechanisms is mainly handled by Kyocera. LED is a special product for this product. In order to reduce costs, the purple LED chip uses a general-purpose product that Kyocera has already produced, and only the resin case portion such as a fluorescent material is used as a special product. At present, the two companies are discussing the launch of new lighting fixtures such as chandeliers and ceiling lamps as needed.

4, "change your face" Sony launched CLEDIS new technology

Sony has demonstrated its CLEDIS screen technology at two international exhibitions this year, a new technology that has been described as capable of challenging OLEDs. The reason why it can claim to have the capital of the OLED is due to the extremely high brightness specifications of the Sony CLEDIS display and excellent color performance. In fact, CLEDIS technology is a small-pitch LED display technology. Sony's small-pitch LED display based on 1.2mm pitch is different from liquid crystal display technology. The small-pitch LED display becomes a single pixel through the combination of RGB three-color LED devices, and encapsulates multiple pixels into screen elements. Drop multiple elements to form a complete display unit. Finally, the large-size LED screens we see are mostly formed by seamlessly splicing these display units.

It is understood that due to the need to high-speed packaging of small three-color LED pixels, and finally achieve a certain resolution display effect, it is necessary to achieve seamless splicing in the middle of multiple display units, so the technical requirements for equipment technology and circuit design are very high. It is reported that in 2016, Sony's small-pitch LED technology has changed its face and appeared in the form of “CLEDIS” technology, and its positioning for consumer users has also changed. Sony CLEDIS display technology is currently available for the commercial application market. Due to its combination of ultra-high brightness, seamless splicing and display size, there is almost no limit in the outdoor display industry, which can bring enough shocking visual effects without worrying about the influence of ambient light. And can meet the needs of high-end display applications, such as in museums, galleries, etc.

5, test LED-based aerial hair core machine icing detector

According to reports, although researchers have made great progress in understanding the high-altitude icing phenomenon of aero-engine core machines in recent years, the work of developing reliable sensor systems that provide dangerous warnings for pilots is still relatively initial. Unlike conventional engines and aircraft, which are frozen by liquid water in visible water vapor at medium and low altitudes, current weather radars cannot detect meteorological conditions that cause the core engine to freeze due to ice crystal accumulation. In some cases, the pilot will be prompted for ice crystals, such as the static accumulation of ice crystals and changes in the frequency of the cockpit noise, which is too late to avoid potentially dangerous areas. To this end, the Podium Aerospace Division of Canada's Podium Energy Group recently announced details of a Reflective Material Sensor (RMS) system that uses light reflectivity to detect ice accumulation. This sensor features an all-solid structure with no moving parts, making it simpler and more durable.

Podium's detector system uses a pair of LEDs to drive the beam through a small window on the engine casing into the flow channel. When the ice crystals accumulate on the surface of the optical window, the photodiode mounted between the LEDs will experience the change in brightness of the reflected light. , thereby detecting the growth of ice crystals. At the same time, the corrosion protection and temperature detection functions are integrated on the upstream side of the optical window. This sensor is directly connected to the engine's full authority digital control system and can also be connected to the engine indication and crew warning system. The sensor activates the airflow heating function of the guide vanes in real time and opens the adjustable deflation valve for deicing. The sensor's dual LED configuration allows flexible calibration in different ambient lighting and the entire system is highly integrated, eliminating the need to mount measuring probes close to the guide vanes or other engine components. In addition, the sensor system does not have a significant impact on engine performance. The LEDs and photodiodes used are only 3 mm in diameter and the optical window is only about 13 mm in size.

6, Apple or develop a thinner and brighter Micro- LED screen

Earlier reports said that the new iPhone in 2017 will use OLED curved screen, but this may only be Apple's transition phase, because Apple is currently developing more advanced Micro- LED technology . According to rumors, Apple will get a mature Micro- LED display in the second half of 2017. In fact, Apple set up a secret laboratory in northern Taiwan last year to develop thinner, lighter, brighter, more energy-efficient display screens, and has plucked many talents from AU Optronics and Sollink. It can be seen that there is a lot of evidence that Apple's eyes are not limited to OLEDs. It is known that Apple also acquired the Micro-LED screen technology company LuxVue in 2014. Like OLEDs, Micro-LEDs are self-illuminating and have the characteristics of low power consumption and fast response. At the same time, they are more energy efficient than LCDs. However, there are still some difficulties in mass production of Micro-LED screens.

According to reports, Micro-LED technology is a miniaturized LED array structure with self-luminous display characteristics, featuring high brightness, low power consumption, small size, ultra-high resolution and color saturation. In addition, Micro-LEDs have a long life and materials are not easily affected by the environment and are relatively stable, but they are not as flexible as OLEDs. Although the rumors have pointed out that the iPhone screen will undergo tremendous changes in the year, for reliability, Apple should not use OLEDs for a long time instead of LCDs. In fact, Micro-LED technology may be what Apple wants most. Interestingly, in the past, AppleWatch watches took the lead in adopting OLED screens, and the iPhone followed. Perhaps in Micro-LED technology, Apple may first use it on watches and then push them to mobile phones.

7, Saphlux research and development technology "made a very bright LED"

In the field of LEDs, the inherent polarization effect of the first-generation GaN solid-state lighting materials will cause the unit brightness of the LED chips to be too low, resulting in a large number of chips required for their corresponding end products, and cannot meet the needs of high-power applications. Although the first generation of solid-state lighting materials based on c-plane GaN has encountered bottlenecks, a new generation of semi-polar GaN materials theoretically realizes ultra-high power single LED chips, but it has not been able to solve mass production problems. The price remains high. To this end, Saphlux has developed a new technology that can directly grow semi-polar gallium nitride on standard large-size sapphire substrates, solving the mass production problem.

Because of the traditional growth mode, semi-polar materials can only be achieved by chamfering bulk GaN (which also needs to grow on sapphire). This type of preparation is not mass-produced, and small pieces of semi-polar gallium nitride materials are very expensive (up to $2,000) and can only be used for scientific research and cannot be commercialized. To mass produce semi-polar gallium nitride materials, a new method is needed to control their growth on sapphire. It is said that Saphlux has finally found a solution (which involves the inconvenience of disclosure of trade secrets) through many experiments, breaking the growth mode of the original semi-polar gallium nitride material, which can grow directly on the standard large-size sapphire substrate. Semi-polar gallium nitride also directly controls the direction and shape of crystal growth.