Compared with mercury lamp, apart from price, it has many advantages:

1, high reliability, no need to heat up to 100% power ultraviolet output.
2, no toxic substances Mercury will not produce ozone.
3, long life and not affected by the number of switches.
4. UVLED is electroluminescent, direct electro-optic conversion, less loss of energy conversion, standby power consumption is almost zero is its greatest advantage.

Although UVC-LED has so many advantages, its most fatal problem is that the price is too high, and as the wavelength decreases, the price also shows an exponential rise. For 280 nm and 265 nm UVC-LED, a device is calculated by how many milliwatts of mW it can emit, a Japanese brand of UVC device, low power. The price of a milliwatt is about $1-2, an external quantum efficiency of only 2-3% of high-power UVC-LED, about 40-50 mW, and a device costs at least $100-200. This high price greatly limits the application of UVC-LED, unless the need for small sterilization tools, otherwise it is difficult to enter the larger market. However, as mentioned earlier, disinfection or sterilization devices, such as milk bottles, water purifiers, humidifiers and so on, are mainly available for installation and carrying on the market at present.

But why is the price of UV so expensive for so many years? Maybe technology is the biggest obstacle for UV-LED!

Apart from full-length UVA-LEDs with wavelengths above 385 nm, the biggest problem for UV LEDs is that the manufacturing process is complex and the price is too high, which needs to start with the nature of the LED industry.

We know that after the development of GaN LEDs in the past two decades, the price and market share of LED with different wavelengths are mainly affected by the technical threshold. The shorter the wavelength, the higher the technical requirements, so UV-B, UV-C-LED price is about 10 times the price of UV-A band LED, UV-A in the main application of 365 nm wavelength LED price is another major application of 385-405 nm LED 2-3 times. There is no essential difference in the cost of production between UV and Blu-ray products. The main reason why the price difference is so great is that the input of product research and development is very different.

Interestingly, the difficulty of developing products in different bands is basically proportional to the price, while the performance and price of LED in different bands are inversely proportional. 365-405nm in UV-A can also be used as gallium nitride (GaN) and indium gallium nitride (InGaN) with high luminous efficiency. UV-B and UV-C use low-luminescent aluminum gallium nitrogen (AlGaN) instead of the familiar gallium nitride and indium gallium nitrogen, which absorb ultraviolet light below 365 nm. So the luminescence efficiency of UVB-LED and UVC-LED will be much lower. From the reported results, the luminous efficiency of UV-B and UV-C bands is 10-20% of that of UV-A, and 365 nm is 50-70% of that of 385-405 nm.