Germicidal led light
Ultraviolet germicidal radiation (UVGI) is a disinfection method that uses short-wavelength ultraviolet (UV-C) light to destroy or inactivate microorganisms by destroying nucleic acids and destroying their DNA, thereby preventing them from performing important cellular functions.  UVGI is used in a variety of applications, such as food, air and water purification.
Because the ozone layer in the atmosphere blocks ultraviolet rays, the ultraviolet rays on the surface of the earth are very weak.  UVGI equipment can generate strong UV-C light in the circulating air or water system, making them unsuitable for microorganisms such as bacteria, viruses, mold and other pathogens. UVGI can be used in conjunction with filtration systems to disinfect air and water.
Since the mid-20th century, the application of UVGI for disinfection has become a recognized practice. It is mainly used in medical hygiene and aseptic workplace. Since the containment equipment is closed and can be recycled to ensure higher exposure to ultraviolet rays, it is increasingly used for disinfection of drinking water and wastewater. In recent years, UVGI has found new applications in air purifiers. Since the first introduction of incandescent bulbs, the invention of solid-state lighting, especially the development of white LEDs, has been driving the most significant changes in the field of lighting. The headlines or the significant impact of light-emitting diodes (LEDs) on society include energy efficiency and environmental benefits. In addition, the versatility of design choices brought by the compact nature of LEDs has been widely used in many industries including consumer, automotive, commercial and industrial. Similarly, the performance improvement of deep ultraviolet (UVC) LEDs is driving innovation in drinking water disinfection systems as these devices begin to meet the economic requirements of POU systems in terms of power, service life and price. UVC LED provides designers with a more effective light source for sterilization. As UVC LEDs are gaining more and more attention in these applications, there are new challenges in how to calculate the required power output, because traditional mercury-based lamps cannot be replaced one-on-one. By understanding the impact of LED spectral emission on the spectrum of microbial action, engineers can develop highly compact, more durable and effective disinfection systems.
UVC LED can provide the correct sterilization wavelength
In ultraviolet disinfection, light in the range of 250-280 nm is the most effective for inactivating the DNA of microorganisms, making them unable to reproduce. (Traditionally, POU system designers rely on low- and medium-pressure mercury arc lamps to achieve this sterilization range.) Low-pressure mercury lamps emit a single output at 253.7 nm. The total output power of the lamp is equal to the output power in the UVC range, even at non-optimal wavelengths. The medium-pressure mercury lamp emits a wider wavelength range, including the sterilization range, but also includes unnecessary disinfection wavelength purposes (as shown in Figure 1). In fact, only about 20% to 30% of light is emitted in the UVC range. On the other hand, the continuous spectral response of UVC LEDs is mainly in the required UVC range, so that a more efficient system can be realized.
Application of sterilization power in commercial production
As the application of UVC LEDs expands, the number of providers will increase. This will provide OEMs with more choices, but will also change the provider's product specifications. Throughout the product development or design process, engineers may tend to observe each spectrum of a single light source to determine the best benchmark performance standard. However, high-volume manufacturers require a more systematic way to specify sterilization output power. This method of convolution (ie, standardizing LED output in terms of sterilization power) has the desired effect.
Although complex microbial systems do not have a method that can meet all needs, this is an advancement in simplification that allows engineers to create reasonable designs for manufacturability. High-performance UVC LEDs enable manufacturers to transition from mercury lamps to solid-state lighting solutions. The higher efficiency and compact footprint of the UVC LED sterilization wavelength can achieve a more effective disinfection system. Because it can reduce pathogens by more than 99.99%, UVC LEDs have proven effective in water disinfection. There is no doubt that these light sources are a viable alternative to traditional methods and will continue to develop in innovative new designs.