Development of silicon substrate LED technology to form independent innovation brand

Ministry of science and Technology (State Bureau recently issued a plan (2011) No. 5), decided in the country set up 29 new National Engineering Research Center, the National Engineering Research Center for silicon-based LED become the formation of projects, relying on units of Nanchang University. This is China's first national LED engineering technology research center. The formation of the National Engineering Center aims to improve the capability of industrialization, the new center project, improve the open service capabilities, to promote the new center of the technical progress of the industry through a variety of ways, to achieve the combination of science and economy. The establishment of the national silicon based LED engineering technology research center will effectively promote the realization of this technology with independent intellectual property rights in the real sense of large-scale industrialization.

Light emitting diode (LED) is the use of an electronic component of electron and hole in semiconductor light-emitting compound, is a cold light source, energy saving and environmental protection. From the beginning of the first LED in 1960s, after 40 years of efforts, has achieved the red, orange, yellow, green, green, blue, purple color LED production and application. Especially the birth of 1994 high brightness blue LED, opened a semiconductor lighting lamp (white LED) prelude to gradually replace the incandescent lamp, the existing fluorescent lamp for general lighting, the lighting industry is causing the revolution, this is a sign of the progress of human civilization. In this area, Japan and the United States to take the lead, monopolize sapphire and silicon carbide substrate of LED lighting technology.

Nearly three of China's five year plan in many kinds of science and technology and industry planning are arranged a plurality of topic tracking which is a high technology frontier. It is gratifying to see that this field from the track on the cross, part of the core technology in the international leading position, with the original innovation. Nanchang University luminescent materials research and engineering of Ministry of Education Center in electronic devices, development fund and the "863" plan under the support of the creative development of a new semiconductor lighting technology roadmap - silicon substrate LED lighting technology, changes in Japan and the United States monopoly of the core technology of LED lighting situation.

The research group in the field of semiconductor lighting research and development in 10 years, 7 years before the track, spanning nearly 3 years. They invented a special transition layer and the specific surface of the silicon processing technology, to capture a number of international problems in the first generation of semiconductor silicon materials, the successful preparation of quantum well structure of high quality in the third generation of semiconductor GaN materials were prepared, the successful development of the vertical structure of GaN blue LED, white light efficiency can reach 100 lumens per watt. The technical indexes of the luminous efficiency, reliability and lifetime of the device in the international leading position in the similar research, and the first to achieve mass production, successfully used in street lamp, bulb, lamp and flashlight etc.. In this field, they have obtained more than 60 patents. The cost of LED lighting chip produced by this technology is significantly lower than that of sapphire substrate and silicon carbide substrate LED chip. This technology is a kind of new technology, which is a kind of new technology for LED and LED, which is a kind of disruptive technology for LED.

Now, LED chip for semiconductor lighting by epitaxial substrate is divided into three routes, namely the sapphire substrate LED technology, silicon carbide substrate and silicon substrate LED technology, LED technology roadmap. These three technical routes are in strong R & D and production, before the two technical route is relatively advanced, third technical routes compared with the previous two technical routes, the level of the gap is narrowing, it is unclear which route will be the ultimate semiconductor lighting technology. But there is a common feature, the best performance of power type LED devices, all went to the "stripped substrate will be transferred to the epitaxial film epitaxial substrate" to prepare the vertical structure of the LED chip technology route. The main reason is that the transfer of the vertical structure of LED stripping process for the preparation of high reflectivity and high light efficiency of the surface roughening technology provides a convenient, at the same time because the p-n node from the new substrate with good heat dissipation performance (substrate) is very close, very conducive to the heat dissipation device, which helps to improve the device the service life, but also conducive to the increase of current density devices. In these three technical routes, the silicon substrate technology route can only be removed by a simple wet chemical etching, which is a non damage stripping, very suitable for stripping transfer, is conducive to reducing production costs.

Although silicon substrate LED technology started late, but the unit in just a few years, successfully developed a high performance power LED devices with LED sapphire and SiC substrate LED technology roadmap competition substrate decades history, indicates that the silicon substrate LED technology has great potential for development, has laid an important the foundation for development of semiconductor lighting technology route has Chinese characteristics.

Currently used at home and abroad, third technical routes for LED lighting chip development more and more, some international LED companies have joined the ranks. Some international experts have even asserted that the silicon substrate LED technology route is the future of semiconductor lighting chip production of the ultimate technical route. Therefore, the competition of the core technology of semiconductor lighting triggered by the new technical route is being lifted all over the world. Although the leader in this field in China, but did not light the "enemy", but also to the mature product at top speed, the expansion of production scale, but also increase research and development efforts, continue to enhance the luminous efficiency, high-end chip development more cost-effective, to keep the sustainable development of enterprises good