At present, the appearance of deep UV LED is a rigid substitute for mercury lamp widely used in the market. The traditional ultraviolet light source generally uses mercury vapor discharge to generate ultraviolet light by using the excited state of mercury, which has many defects, such as high power consumption, high calorific value, short life, slow reaction, potential safety hazard and so on. The emerging deep UV light source uses the principle of LED, which is called deep UV LED.
Compared with the traditional mercury lamp, the new deep UV LED has many advantages. First of all, the structure of deep UV LED is simple, without fragile glass shell, portable and shock resistant, and the working voltage is only a few volts, without complex driving circuit. Secondly, deep UV LED turns on quickly without preheating, which is very suitable for fast detection, high-speed communication and other applications. Compared with the traditional mercury lamp, the deep UV LED has a single emission peak, and the emission wavelength can be adjusted continuously. In terms of environmental protection and energy saving, deep UV LED materials do not contain harmful substances to the environment, which is environment-friendly. At the same time, compared with traditional UV light sources, deep UV LED can save up to 70% of energy, and meet the requirements of EU harmful substances limit (ROHS standard). Finally, the life of deep UV LED has been able to reach more than 5000 hours, exceeding the life of mercury lamp. Therefore, on the one hand, it is an inevitable trend of social development to vigorously promote the research and development of deep UV led to replace the traditional UV light source. On the other hand, the application potential of deep UV LED will far exceed that of mercury lamp and can penetrate into more application fields.
On January 19, 2013, the United Nations Environment Programme (UNEP) passed the Minamata convention, which aims to control and reduce mercury emissions worldwide. With the formal entry into force of the Minamata convention in 2020, UV mercury lamps will be banned from production, and UVLED light source is bound to replace UV mercury lamps on a large scale. Therefore, the use of UVLED light source must be the trend.
With the continuous development of semiconductor LED industry, the application of deep UV LED in industry, household and military fields is deepening, and the application fields are expanding. The urgent demand for low-cost and high-power deep UV LED in water purification, sterilization, health care, photocatalysis, phototherapy and other fields is becoming more and more obvious. With the reshuffle of the general lighting field in 2016, the focus of major enterprises began to shift to the segmentation field in 2017. It is estimated that the market value of UVC led sterilization and purification applications will reach US $28 million in 2016 and US $257 million in 2021, with a compound annual growth rate of 56%. However, deep UV LED products have a high technical threshold, epitaxy, chip, packaging and market acceptance are facing many challenges.