Ural Federal University: Scientists Created Bright Broad Spectrum Nanoluminescent Phosphors
A group of scientists from Ural Federal University and the Ural Branch of the Russian Academy of Sciences obtained nanoluminophores with a high intensity of light emission for the first time. They can be used in the development of LED devices, lasers, and for creating biological tags for patient health monitoring. An article about the study was published in the journal Results in Optics.
A luminophore is a substance that converts absorbed energy into light radiation. In this case, we are talking about creating nanoscale particles that luminesce from infrared radiation. Luminosity of radiation in new nanoluminophores is 80 times higher than in similar bulk compounds. High efficiency of luminescence will improve fiber lasers for processing various materials, increase brightness of white LEDs – environmentally friendly light sources. Another promising direction is the creation of biological tags to visualize processes occurring in the body.
“Luminophores can be used in various fields, including medicine to visualize various pathologies in tissues and body cells. Due to their optical properties, nanoparticles can be excited directly through the biotissue, and the infrared range light that excites photoluminescence has no harmful effect on the body. However, preclinical studies on animals are needed to determine the efficiency and safety of nanoparticles,” said Mikhail Zuev, professor at the Department of Physical and Colloid Chemistry at Ural Federal University and senior researcher at the Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences.
Scientists figured out that luminescence intensity in nanoluminophores can be increased by means of erbium and ytterbium ions. At a certain concentration of these ions in nanoparticles, a photon avalanche effect occurs, when the absorption of one photon leads to the emission of many others.
“We obtained this composition of nanoscale luminophores for the first time. These are complex silicate nanoluminescent phosphors composed of strontium, yttrium, silicon, and oxygen. We also added triple-charged rare-earth ions of erbium and ytterbium. It is the erbium and ytterbium ions that give a significant increase in the intensity of the red glow due to the photon avalanche effect. We discovered the photon avalanche effect in silicate rare-earth nanoluminescence phosphors for the first time,” Mikhail Zuev notes.
The scientists obtained silicate amorphous nanoluminophores by electron beam evaporation of bulk samples. They first applied this method to silicate luminophores containing europium ions. Reduction to the nanoscale state resulted in a color change of the photoluminescence.