White LED with high light efficiency, long life, energy saving, environmental protection and other significant advantages of green lighting and information display has broad application prospects in the field. At present, the core material of the commercial white LED blue LED chip and phosphor are two, are indispensable. Although there are a number of optional technical solution, but the development trend, the phosphor of the blue LED chip has been the mainstream production of the white LED. Therefore, the phosphor is crucial in terms of industry, governments, research institutions and industry attaches great importance to put a lot of manpower, material research and development of LED lighting and LCD display.
Initial breakthrough of foreign patent restrictions
At present, rare earth cerium-activated garnet structure of aluminum acid the yttrium yellow phosphor with a blue LED to produce white light-emitting efficiency is best, however, the phosphor luminescence in the red part is a serious shortage, resulting in color than white LED products poor, can not use the single phosphor preparation of low color temperature, high color rendering white LEDs. Yellow powder product of the "blue chips as a light source in the visual feel too cold; as the LCD backlight, the display color gamut narrow, full-color effect using" white LED devices produced by the blue chips Rhubarb Pink display index although a substantial increase (80), but to get a higher index (90), must also be a green phosphor.
LED phosphor development process, sulfide, sulfur oxides, tungsten molybdate, germanate and arsenate, scandium silicate and so has been to develop and try to apply their own existence but these systems phosphor poor stability, low excitation efficiency, and cost disadvantages, and none has been widely used. Acid, aluminum, yttrium yellow powder with its high luminous efficiency and excellent structural and chemical stability will continue to play an irreplaceable role, nitrides and oxides of nitrogen, phosphor, with its unique structure, excellent luminous performance and stability become white LED red and green phosphors R & D and promote the use of focus.
Our specialized system to carry out research and development of LED phosphor late start, the foreign patents of LED phosphors to occupy a favorable position. Such as a phosphor of Yttrium aluminum garnet structure is more conventional phosphor materials, because of its ultra-short afterglow characteristics in the 1960s has been widely used in the flying spot scanner, and thus the phosphor itself is not patent problem. In 1997, Nichia GaN chip with phosphors to obtain white light and patented. Silicate materials Another example is commonly used in LCD backlight white LED in the early widely used as a long afterglow materials, but later in the LED silicate phosphors patent layout, foreign and went in front. Domestic study of rare earth and Dalian Luming initial breakthrough in the the aluminate meal, green silicate powder foreign patents to restrict development in recent years, product quality is quite basic and the level of foreign. Nitride / nitrogen oxide phosphors for a wide range of high luminous efficiency, good chemical and thermal stability, with good market prospects as LED red and green phosphors with excitation and emission. Occupied the advantage in the nitride / NOx system patents, Japan's Mitsubishi Chemical and other foreign companies, there is research of rare earth and other units on the composition of the nitride / oxides of nitrogen, phosphor, preparation process has been systematically studied, but also to apply a series of patents.
Focus on quality rather than price
And energy-saving lamps trichromatic phosphor LED phosphor is unique. First, only the white LED devices cost 1% to 2% of LED phosphors, LED packaging manufacturers are primarily concerned with product quality, not price, and thus survive LED phosphors on the market only a first-class products; two LED chips and packaging technology continues to progress, requires phosphor performance corresponding to continuous improvement and change, companies can survive only with deep R & D accumulation and strong ability to continuously innovate; China's LED products exports rather than domestic, on the phosphor the requirements of the patent, the patented phosphor is difficult to enter the market. For these reasons, although domestic manufacturers claimed that the production of LED phosphors no fewer than 20 have research of rare earth and a few other products to enter the market, the market of white LED phosphors is basically the fundamental chemistry of Japan (market brand for Taiwan Hongdae ) and Intel occupied by the United States, less than 20% of the market share of domestic white LED phosphor. In recent years, Mitsubishi Chemical, Japan With the advantages of the nitride Pink is rapidly seize market share, and has recently announced to set up plants in the production of LED phosphors in Xi'an.
The study of rare earth in the phosphors developed over 40 years of history, engaged in R & D of LED phosphors 10 years of history, aluminate, silicate, aluminum silicate, nitride phosphor system and related LED devices applied for more than 30 invention patents in China and more than 10 foreign patents for inventions, has more than 10 invention patents and five foreign invention patents authorized. Through the licensing of patents to protect the export interests of the domestic packaging manufacturers.
