Japanese research develops new technology that can significantly reduce the cost of deep ultraviolet LEDs

　　Ritsumeikan University in Japan recently published a communiqué stating that its researchers have developed a technology that can efficiently produce deep ultraviolet light-emitting diodes (LEDs) at a very low cost, which is expected to become a widely adopted deep ultraviolet light source following the United Nations' restrictions on the use of mercury.

　　Ultraviolet light with wavelengths between 200 nanometers and 350 nanometers is called deep ultraviolet light, and is widely used in fields such as air sterilization in water treatment plants, hospitals, and factory cleanrooms, as well as formaldehyde treatment. In the past, many deep ultraviolet light sources used mercury lamps, but the Minamata Convention on Mercury, signed by various parties under the auspices of the United Nations last year, stipulates that the use of mercury must be significantly restricted. Therefore, it is necessary to develop alternative light sources.

　　Deep ultraviolet LEDs can be used to replace mercury lamps, but in the past, expensive sapphire had to be used as a substrate when manufacturing deep ultraviolet LEDs, and its high cost limited their widespread adoption. Senior researcher Katsunobu Aoyagi of Ritsumeikan University and others reported that inexpensive silicone can be used to replace sapphire as a substrate, thereby significantly reducing costs.

　　In addition, in previous processes, to allow current to pass through, part of the insulation layer on the substrate had to be stripped away. The new method, however, involves applying a layer of aluminum nitride to a silicone substrate as an insulator, and then opening multiple micro-holes on top to allow current to pass through. This eliminates the need to strip the insulation layer, significantly shortening the manufacturing process — what previously took 5 days of production work can now be reduced to 1 day. It also avoids damage to LEDs during the insulation layer stripping process, improving luminous efficiency.

　　The research group believes that the new method can significantly reduce the manufacturing costs of deep ultraviolet LEDs, and is expected to promote the large-scale production and widespread application of this deep ultraviolet light source.