MOSCOW, Apr 13< /strong>Young employees of the Far Eastern Federal University (FEFU, Vladivostok) have figured out how much faster and easier it is to manufacture energy-efficient super-bright LEDs used in underwater and aircraft, in the automotive industry, as well as for search and rescue operations, the Russian Science Foundation (RNF) reported.
In the manufacture of high-power white LEDs for cars, submarines, tunnels and airfields, ceramic forms of light-converting substances — phosphors — are used.
White LEDs are widely used in everyday life, but they are not powerful enough. Their commercial versions contain phosphors — light converters based on yttrium aluminum garnet with the addition of cerium. However, due to the inhomogeneous application and low thermal conductivity, such structures glow with an inhomogeneous color and «burn out» during use. At the same time, for underwater and aircraft, automotive, search and rescue operations, it is not so much energy efficient as super-bright white LEDs that are needed.
Phosphors in such devices should be thermally stable, compact and durable, and their composition and shape should not harm the environment during operation and subsequent disposal. One of the advanced forms of phosphors is ceramic. It is made at sufficiently high sintering temperatures, and the process itself takes a long time.
A team of young employees of FEFU has created a phosphor based on optical quality ceramics. At the same time, the authors optimized its composition, proposed an innovative method for sintering the initial components, and learned how to regulate the microstructure of the final material.
In the new work, the scientists have proposed a new approach that makes it possible to obtain such materials at temperatures 20% lower than usual and reduce the overall duration of the process by 10-20 times. The authors developed their method using widely available commercial powders as raw materials. At the same time, they formed a material with a controlled fine-grained structure, and its luminescence efficiency was higher than that of known analogues, exceeding a record 80%. The results of the study, supported by a grant from the Russian Science Foundation, were published in the international scientific journal Journal of Advanced Ceramics.
«Now we are engaged in the production of serial prototypes and models of lighting devices based on them. In the future, we plan to move to the stage of development and technological work with the involvement of industrial partners,» said the project manager, candidate of technical sciences, professor of FEFU Denis Kosyanov, Director of the Scientific and Educational Center «Advanced Ceramic Materials».