9 questions to take you to understand UVC LED

UVC LED sterilizer

According to LEDinside's "2018 UV LED Application Market Report-Curing, Medical, Sterilization", the output value of the UV LED market grew to US $ 223 million in 2017, and it is estimated that it will reach US $ 1.224 billion in 2022, with a compound growth rate of 2017-2022. 33%. In addition to the steady growth of the curing market, surface sterilization, still water sterilization, and flowing water sterilization are the main growth drivers for the five years of 2018-2022.

Today, let us talk about these core players in the main growth momentum: UVC LED.

1. What is UV?

First, let's review the concept of UV. UV, or Ultraviolet, or ultraviolet, is an electromagnetic wave with a wavelength between 10 nm and 400 nm. UV in different bands can be divided into UVA, UVB, and UVC.

UVA: The wavelength is longer, the wavelength is between 320-400nm, can penetrate the cloud layer, glass into the room and the car, can penetrate to the skin dermis layer, it will cause tanning. UVA can be further subdivided into UVA-2 (320-340nm) and UVA-1 (340-400nm).

UVB: The wavelength is in the middle, the wavelength is between 280-320nm, it will be absorbed by the ozone layer, it will cause sunburn and skin redness, swelling, heat and pain.

UVC: The wavelength is between 100-280nm, but because the wavelength below 200nm is vacuum ultraviolet, it can be absorbed by air, so the wavelength of UVC that can pass through the atmosphere is between 200-280nm, the shorter the wavelength, the more dangerous, but because of Can be blocked by the ozone layer, only a small amount will reach the surface of the earth.

2. The mechanism of UV sterilization?

UV can destroy the DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) molecular structure of microorganisms, make the bacteria die or cannot reproduce, so as to achieve the purpose of sterilization.

3. UV sterilization band?

According to the International Association of Ultraviolet Lights, "The ultraviolet spectrum ('sterilization' area) which is very important for water and air disinfection is the range that is absorbed by DNA (RNA in some viruses). This sterilization band is about 200-300nm."

It is known that the sterilization wavelength extends above 280nm, and it is now generally considered to extend to 300nm, however, this may also change with more research. Scientists have proved that ultraviolet light with a wavelength between 280nm and 300nm can also be used for sterilization.

4. What is the most suitable wavelength for sterilization?

There is a misunderstanding that 254nm is the best wavelength for sterilization, because the peak wavelength of the low-pressure mercury lamp (only determined by the physics of the lamp) is 253.7nm. In essence, as mentioned above, a certain range of wavelengths has a bactericidal effect. But it is generally considered that the wavelength of 265nm is the best, because this wavelength is the peak of the DNA absorption curve. Therefore, UVC is the most suitable band for sterilization.

5. Why did you choose UVC LED in history?

Historically, mercury lamps were the only choice for UV sterilization. However, the Minamata Convention on Mercury has officially entered into force in China since August 16, 2017. The Convention requires that from January 1, 2021, the production and import and export of mercury-containing products shall be prohibited, while mercury lamps Also in this column. Therefore, there is not much time left for mercury lamps, and UVC LED is the only reliable alternative that seems to be today.

Of course, this kind of change is also everyone's favorite, and the miniaturization of UVC LED components brings more imagination to the application scenarios, many of which are impossible to achieve with traditional mercury lamps. In addition, UVC LED has many advantages such as fast startup, more switching times allowed, and battery power.

6. UVC LED application scenarios?

According to LEDinside's 2018 UV LED Application Market Report-Curing, Medical, and Sterilization, surface sterilization, still water sterilization, and flowing water sterilization will become the main growth drivers for the next five years from 2018 to 2022 outside the curing market in the next five years. According to different application scenarios, we may see UVC LED in these applications in the future:

Surface sterilization: high-frequency public contact surfaces such as medical appliances, maternal and child products, smart toilets, refrigerators, tableware cabinets, fresh-keeping boxes, smart trash cans, thermos cups, escalator handrails and ticket vending machine buttons, etc .;

Still water sterilization: drinking water tank, humidifier, ice maker;

Mobile water sterilization: mobile water sterilization module, direct drinking water machine;

Air sterilization: air purifier, air conditioner.

7. How to choose UVC LED?

Can be selected based on parameters such as optical power, peak wavelength, lifetime, and beam angle.

Optical power: The available UVC LED optical power in the current market ranges from 2mW, 10 mW to 100 mW. Different applications have different power requirements. Generally speaking, the optical power can be matched with the irradiation distance, dynamic demand or static demand. The greater the irradiation distance, the more dynamic the demand and the greater the optical power required.

Peak wavelength: As mentioned above, 265nm is the best wavelength for sterilization, but considering that the average peak wavelength of each manufacturer does not differ much, in fact, optical power is the most important indicator to measure the sterilization efficiency.

Life: According to the application time of the specific application to consider the demand for life, find the most matching UVC LED, the best is the best.

Light angle: The light angle of the lamp beads with a flat lens package is usually between 120-140 °, and the light angle with a spherical lens package is adjustable between 60-140 °. In fact, no matter how large the angle of UVC LED is, you can design enough LEDs to completely cover the required sterilization space. In scenes that are not sensitive to the scope of sterilization, a small angle of light can make the light more concentrated and the sterilization time is shorter.

8. What are the technical challenges facing UVC LEDs?

Throughout the above, UVC LED seems to be all very beautiful, "true fragrance"!

However, like all things in development, it also faces the trouble of growth. From epitaxy to chip to packaging, UVC LEDs are all facing challenges.

Technical matters, welcome to the end to sign up for the 2019 Jibang Consulting Global UV LED Industry Seminar. On April 17th, chat with the colleagues and experts present. The editor will not talk about it here (mainly it cannot be opened).

9. What is the biggest challenge of UVC LED application?

Because of the many technical problems currently existing in UVC LEDs, the cost of UVC LEDs remains high, from chips to materials. Therefore, the biggest challenge that hinders the application of UVC LEDs can be described as: expensive.

Of course, like all things in development, it is only a matter of time before UVC LEDs fly into ordinary people's homes with the development of future technology.

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Beijing Torch Co,. Ltd has developed an elevator deep ultraviolet sterilization and disinfection system, a taxi deep ultraviolet sterilization and disinfection system, a deep ultraviolet central air conditioning sterilization module, a mask / mobile phone deep ultraviolet sterilization and disinfection treasure, and a deep ultraviolet sterilization. A series of products such as disinfecting toilet lids, deep ultraviolet sterilization and disinfection medical garbage cans, subway deep ultraviolet sterilization and disinfection robots, vehicle-mounted anti-virus fans, etc. have achieved staged success. In the recent launch experiments, they have obvious effects and can fully meet the public The needs of different scenarios such as transportation, public places and home protection. I believe that in the near future, such physical sterilization and disinfection instruments will replace chemical disinfectants with higher efficiency and better user experience to protect our health and safety! Welcome everyone to discuss cooperation