Russian scientists have made a breakthrough in the chemistry of rare earth elements: they have learned to control their luminescence, changing the color and brightness of the glow. This discovery could lead to more efficient light sources, next-generation displays and compact lasers.
A group of researchers from the National Research University Higher School of Economics and the Institute of Chemical Chemistry of the Russian Academy of Sciences discovered that using a special chemical environment it is possible to change the glow properties of rare earth metals. For example, cerium, which traditionally emits in the ultraviolet range, began to glow yellow under new conditions. The research results were published in the authoritative journal Optical Materials.
Rare earth elements (lanthanides) are widely used in modern technologies: in the production of LEDs and energy-saving lamps, phosphors for displays, laser systems…
Their value lies in their ability to emit light of a strictly defined color. However, until now it was believed that this color cannot be changed. Russian chemists have refuted this claim.
When an atom receives energy (from light or electricity), its electrons move to a higher level and then return back, releasing the excess energy in the form of light.
Typically, the glow occurs due to transitions between 4f orbitals, which are protected from external influence. Therefore, the color of the radiation is always constant.
By creating special chemical compounds with organic ligands, the researchers were able to exploit 5d orbitals that are sensitive to external influences. This allowed us to “reconfigure” the color of the glow.
Practical results
– Cerium: instead of UV radiation (300-400 nm) – red glow (655 nm)
– Similar changes were achieved for praseodymium and terbium
– A technique has been developed for predicting the emission spectrum for different compounds
“Previously, we observed a color change, but did not understand the mechanism. Now we can purposefully create materials with the desired properties,” explains Daniil Bardonov, co-author of the study.
1. Optoelectronics: more efficient LEDs with adjustable spectrum
2. Displays: improved color reproduction and energy efficiency
3. Lasers: compact radiation sources with adjustable parameters
“This is a fundamental discovery that opens the way to the creation of completely new materials,” says Dmitry Roitershtein, head of the study.
Experts believe that the development of Russian scientists can reduce the time and costs of creating optical materials, since now their properties can be predicted at the design stage.
Source: naked-science.ru
Photo: iStock
