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Information × Registration Number 0221U101137, 0120U103679 , R & D reports Title Development of vanadate nanoparticles for collecting light from the ultraviolet range. popup.stage_title Head Chukova Oksana V., Кандидат фізико-математичних наук Registration Date 15-01-2021 Organization Taras Shevchenko National University of Kyiv popup.description2  The object of research - the processes of absorption and conversion of excitation energy in nanoparticles of orthovanadates of composition La1-uSauVO4, La1-uVauVO4, La1- xRExVO4, La1-x-yRExCauVO4, which are promising luminescent materials. The aim of the work is to develop vanadate nanoparticles with compositions characterized by increased ability to absorb and luminescent conversion of light from the near ultraviolet range of the spectrum, and to establish the chemical and physical processes responsible for the occurrence specified properties. Concentration series of nanoparticles of vanadates of composition La1-ySauVO4, La1-yBauVO4, La1-xRExVO4, La1-x-yRExSauVO4, where RE = Sm, Eu, Er, Yb, were synthesized by a modified sol-gel method. Their morphological, structural, crystal chemical and optical characteristics were studied, for which the following methods were used: X - ray phase analysis, scanning electron microscopy, optical and luminescent spectroscopy. Based on the obtained experimental data, the effect of impurities on the ability of vanadate nanoparticles to absorb and fluorescent light from the near ultraviolet and visible violet ranges of the spectrum was studied, the processes of excitation energy transfer from the matrix to luminescent impurities were studied. The basic optical properties of the synthesized samples, in particular, the spectra of diffuse reflection, radiation and luminescence excitation, have been studied. Diffuse reflection spectra consist of a broad band in the vicinity of 300 - 350 nm, which corresponds to the internal transitions in the vanadate anion VO4 3-. It was found that the location of the reflection edge shifts to the long-wavelength region with increasing concentration of Ca2 + and Ba2 + impurities, but for Ca2 + this effect is better, so only Ca2 + impurities were introduced into samples doped with REE activators. Product Description popup.authors Voitenko Tetiana A. Dorofeeva Anna I. Nedilʹko Sergiy G. popup.nrat_date 2021-01-15 Close