Human life is long and the process of all kinds of symbiotic bacteria and struggles. Such as probiotics can promote the balance of bacteria in the body, so as to let the body more healthy, and harmful bacteria will cause lead to many diseases. Such as air conditioning, humidifier, bathroom, kitchen, etc. Where there is water to clean as long as a little slack, these places will be bacteria.

One, the light of the future "deep ultraviolet (uv)"

A new generation of advanced technology "deep uv LED (light-emitting diode) can release bactericidal effect, and the light invisible to the naked eye. The bactericidal effect of light, called deep ultraviolet light. Now developed mainly in the field of LED release "UV - C", which is 100 ~ 280 nm (nano, 1 billion per 1) the type of light.

Deep ultraviolet power would have been verified. Deep ultraviolet (uv) that can be applied directly to the basis of life - DNA, radically cut off bacteria breeding. Studies have shown that the wavelength of 260 nm uv is easily absorbed by DNA. Have to eliminate the effect of the DNA genetic information.

Second, the deep ultraviolet development situation

The development of deep uv technology mainly in the United States, Japan, South Korea and other countries. In 2014, the red battery yong due to developed the blue leds and amano hao won the Nobel Prize in physics. With the Nobel technology source, Japan stand in the forefront of deep uv development at present. Ahead of the United States in the deep ultraviolet research, representative of the enterprise is the SETI company of the United States, but in recent years have overtaken Japan, Japan day machines (NIKKISO) since the spring of 2015 production light wavelength is 255 ~ 350 nm deep uv LED.

From Korea Seoul semiconductor and LG Innotek also in research and development of uv LED. At the same time Japan's information and communications research institute (NICT) announced that the newly developed deep ultraviolet wavelength of 265 nm leds, implements the power output up to 90 mw/cm2 continuous light, the power is enough to meet the demand of practical application. As the capture growth market, by improving the luminous efficiency, to establish production technology, achieve cost into the goal, a global competitive technology development. The lead is three Japanese companies: daily machine loading, agms and hill.

The shorter the wavelength uv LED chip light, the greater the technical difficulties, in the field of deep uv LED chip in China also has the excellent enterprise represented by Qingdao Jason. Also represented by hong, the star light electric god remit the middle reaches of packaging companies are planning to launch the respective deep uv LED products.

Three problems, deep uv LED development

UV - LED single chip area is small, easy to flexible design; But the corresponding the radiation power of the single chip is low, in many applications it is difficult to meet the requirements of high radiation power density, which is LED in many areas it is difficult to replace the current UV - one of the main reasons for the UV lamp.

3.1 improve chip luminous efficiency

1) high quality AlN crystals layer

First of all need to solve the UVC LED chip quality AlN module of each band. When making blue leds, sapphire substrate superposition of indium gallium nitride crystal layer. Production of high quality crystal layer, is the key of the realization of mass production and performance stabilization, but it is not easy to indium gallium nitride on the sapphire crystal.

For this reason, people came up with the first set on sapphire gallium nitride buffer layer, top superposition method of indium gallium nitride layer. But, deep uv LED light-emitting material is different from blue leds, adopt aluminum gallium nitride, and the nature of the gallium nitride is easy to absorb ultraviolet light, so the buffer material needs to change to aluminum nitride layer. With the progress of crystal growth technology, high ige (internal quantum efficiency of single crystal AlN gradually mature.

2) AlGaN doping technology research

First high Al consisting of n - AlGaN the performance research. Under different conditions of Al content, the activation energy, the influence of the change of the ohmic resistance and the characteristics of short etc.

The second high Al P - AlGaN various features of research. Studies have shown that Al composition was 70%, will reach 320 Mg of activation energy in AlGaN mev, so new doping technique is decided to UVC LED chip can be the key factor for high power output.

3) uv LED light efficiency technology

AlN substrate refractive index big, light extraction efficiency is very low, so you need to improve chip light extraction efficiency. Therefore put forward the AlN substrate surface formed by the size and basic structure of two-dimensional photonic crystal structure of the same wavelength, the light extraction efficiency reaches do not make this kind of surface processing of 140%, plus size is smaller than the wavelength of nanometer structure combination design. The light extraction efficiency reaches do not make this kind of surface processing of 196%.

3.2 heat ultraviolet resistant encapsulation mode

Because deep ultraviolet photon energy is very big, if use white light encapsulation way, using optical resin encapsulation, under the condition of the high-energy ultraviolet radiation for a long time, optical resin easily yellowing, resulting in UVC LED greatly shorten life.

So the UVC LED encapsulation happen to coincide to adopt inorganic metal or ceramic, glass encapsulation. Through the adoption of inorganic materials for UVC LED encapsulation to avoid because the organic material lead to shorten the life. Hon lee with CMH technology platform, the realization of UVLED all inorganic encapsulation, and puts forward protection gas or vacuum tightness encapsulation, UVC LED chip to provide a stable working environment. For UVC LED encapsulation provides a deep ultraviolet resistance, and cost-effective way of packaging. (CMH C = ceramic pottery and porcelain, M = Metal Metal, H = Glass Glass)

Four, conclusion

Although the use of deep uv market is huge, chip greatly improved its transmission power, stability, but slightly backward for UVC LED packaging technology, therefore to seek a stable and reliable way of packaging has become very urgent. Because of the limitation of organic material, blu-ray encapsulation mode of thinking of DNA needs to be broken, seek a kind of inorganic, high air tightness, the relative price of encapsulation mode is to realize the UVC LED one of the large-scale promotion of restricting factors.

Hope that through the hon, CMH technology platform for UV LED encapsulate, strive to improve the stability of the UV LED. With the help of CMH platform power reliable way of UV LED SMD encapsulation, realize the deep ultraviolet UV LED to protect gas or vacuum encapsulation, stable and reliable implementation of encapsulation, and improve its service life. At the same time with the aid of CMH platform, expand the harsh environment (such as humidity, underwater, etc.) the application of UV LED.