2016-11-23 has been read by two people in Zhaowang.
The development of LED industry is changing with each passing day. How do domestic enterprises grasp new development opportunities under the new situation? How can a new generation of LED lighting technology achieve better light quality? When will LED TV enter the home? At the 15th National Symposium on LED Industry Development and Technology and the 20th16th National Symposium on LED Display Application Technology Exchange and Industry Development held recently, industry experts had a heated discussion on LED industry, market, technology, products and other hot topics from different dimensions. Bian Xiao extracted the main points for the readers.
Peng, deputy head of the working group of semiconductor lighting technical standards of the Ministry of Industry and Information Technology: New solid-state luminescent materials and technologies can not be ignored.
In the new solid-state light-emitting materials and technologies, especially the nano-scale materials that will be industrialized in a few years, the future lighting world will be changed, which will bring great challenges to the existing semiconductor lighting. It will change the future lighting world, which will bring great challenges to the existing semiconductor lighting. Whether it can enter the lighting field or not, the only criterion is to evaluate the comprehensive ratio of products, that is, the ratio of energy saving index, light color quality, reliability and price.
These solid-state developed new materials, especially graphene, phosphorus benzene, two-dimensional semiconductor material MX2, perovskite and so on. , not only has luminescent properties, but also can be used to prepare high-performance electronic devices, sensors, detectors, memories, photoelectric devices and so on. Once the application technology is mature and industrialized, it will be a subversive technological innovation, which will have a far-reaching impact on the electronic information industry.
One is organic light emitting diode (OLED). Organic light-emitting diodes (OLEDs) have good photochromic properties and will soon enter the field of lighting. Seoul Research Institute predicts that the output value of OLED lighting will reach US$ 4.7 billion in 2020, Taiwan Province Institute of Photoelectricity predicts that the ratio of LED to OLED lighting output value will be 3: 1 in 2020, and another expert predicts that it will be one quarter.
The second is laser lighting. There are two different technical routes for laser lighting, namely white laser and future laser lighting. The University of Arizona in the United States has studied a kind of ZnCdSSe with nanometer thickness composed of zinc, cadmium, sulfur and selenium, which ensures the coexistence of crystals. Nanosheets are divided into three parts. Under the excitation of light pulse, it can emit laser with three primary colors of R, G and B, and mix them into white light, which can be used for lighting and optical communication. The light response speed is 10 ~ 100 times faster than that of ordinary LED. Shuji Nakamura, the Nobel Prize winner, has repeatedly stated that laser lighting is the viewpoint of future lighting. This technology is based on semi-polar GaN laser tube combined with advanced phosphor technology, which has the advantages of large current density, smaller chip area, more energy saving, long service life and good directivity, but the price is higher at present. He also believes that white lighting with different technical routes will exist for a long time.
The third type is tungsten wire+nano-optical crystal. Three professors from Massachusetts Institute of Technology published a paper saying that the external nano-optical crystal of tungsten lamp is prepared by traditional deposition technology, laminated on a substrate, reflecting light to the filament, and using infrared heat to make the filament emit full-spectrum visible light, with a luminous efficiency as high as 40% and a high possibility. The original tungsten lamp may return to the lighting field.
The fourth is carbon dot luminescence technology. Recently, two professors from the University of Utah in the United States released that corn residue and bread crumbs were treated in high-temperature and high-pressure solution for 90 minutes to form carbon source CDs, some of which were carbon dots with the size less than 20nm. Suspending CDs in epoxy resin can form LED and become carbon QLED. Its advantages are lower cost than cadmium selenide quantum dots, non-toxic and harmless, and its goal is to produce this carbon QLED on a large scale by using waste.
The fifth is perovskite luminescence technology. Perovskites with nanostructures can be used for luminescent lighting and light display, and also for high-performance electronic devices. There are currently three technical routes. The metal halide perovskite luminescence was studied in Cavendish laboratory of Cambridge University. This material contains lead, carbon-based ions and halogen ions, which are easily soluble in common solvents and form perovskite crystals after drying. The preparation equipment is cheap, simple and easy to operate, and the cost is low. It is proposed that perovskite LED should be industrialized within five years.
Organic halide perovskite luminescence is an inorganic-organic mixture, which is fast and simple to produce and low in cost. At 12V, the luminous brightness reaches 10000 Candeira /m2, but the performance is not stable enough.
All-inorganic perovskite quantum dot LED comes from the research team of Professor Zeng Haibo of Nanjing University of Science and Technology. QLED emits 400 ~ 800 nm visible light, with quantum efficiency greater than 70% and green efficiency greater than 90%, which can realize multi-color electroluminescence such as RGB primary colors. It can be used for luminescence, various displays and laser display.
The sixth is the black phosphorus luminescent technology. The monoatomic layered phosphazene manufactured by Australian National University has semiconductor properties and very strong luminescent properties, and can be used to make PV and LED. Black phosphorus has an energy gap. Stripped and stacked on the silicon substrate, the energy gap can be adjusted by the number of phosphorus layers stacked on the silicon substrate, which will be used to make transistors, sensors, photodetectors, PV and LEDs in the future. Black phosphorus has a potential application prospect, and there are many researchers all over the world. Domestic researchers engaged in this research include Shenzhen Institute of Advanced Technology of Chinese Academy of Sciences, Shenzhen University, China University of Science and Technology, Fudan University and Shanghai Institute of Applied Mathematics.
Seventh, two-dimensional semiconductor material MX2. This is a research hotspot in the field of new materials after graphene. Because of their unique lattice structure and characteristics, these materials have great potential application ability, which has attracted the attention of researchers all over the world.