| Abstract [eng] |
Luminescent materials, also known as phosphors, are widely used in nowadays. Optical technologies, emissive displays, fiber-optic telecommunication systems, lasers, etc. are the area of their major applications. Inorganic phosphors are composed of an inert host lattice and optically active ion (activator), for example, 3d or/and 4f metal ions, such as Cr3+, Ce3+, Eu3+, and Tb3+. Chromium and terbium co-doped yttrium aluminum garnets are perfect candidates for luminescence. Recently it has been noticed that yttrium aluminium garnet co-doped with Tb3+ and Cr3+ ions causes energy transfer from Tb3+ to Cr3+. Garnets solely doped with Tb3+ exhibit low and high spin [Xe]4f8→[Xe]4f75d1 excitation transitions observed at around 250 and 320 nm, respectively, whereas the emission is observed in red, orange, green, and blue spectral regions. Yttrium aluminium garnet co-doped with Tb3+ and Cr3+ ions causes the expansion of the emission region in far red region because of Cr3+ ions. In the present work, the concentration influence of Tb3+ ions on luminescence properties is discussed in detail. The optimal concentration of activator ions is also determined. Furthermore, the kinetics of luminescence, the external quantum efficiency and the color coordinates are also considered. In this case, chromium – terbium co-doped YAG phosphors are more potentially suitable for applications that require a wide emission band and extremely high quantum efficiency. |
