Green-Emitting Gd3Ga5O12: Tb3+ Nanoparticles Phosphor: Synthesis, Structure, and Luminescence

摘要

Nano- and microceramics of Gd~(3)Ga~(5)O~(12) garnet doped with 1?mol?% Tb_(3+) ions were synthesized via co-precipitation and high-temperature solid-state reaction methods. X-ray diffraction measurements confirmed the formation of the garnet structure with Ia3d space group in all investigated samples. Atomic force microscopy surface images and grain-size distribution diagrams of Gd~(3)Ga~(5)O~(12): 1?mol?% Tb_(3+) nanoceramics with 300 and 400?g/mol of polyethylene glycol (PEG) were obtained. The relationship between the content of polyethylene glycol and the particle size of Gd~(3)Ga~(5)O~(12): Tb_(3+) phosphors was revealed. An intense broad band ( λ ~(m)?=?266?nm) related to spin-allowed 4 f _(8)-4 f _(7)5 d _(1) transitions of Tb_(3+) ions was found in photoluminescence excitation spectra of Gd~(3)Ga~(5)O~(12): Tb_(3+) nanocrystalline ceramics with PEG-300 and PEG-400 at 300?K. The broad excitation band caused by spin-forbidden ( λ ~(m)?=?295?nm) 4 f -5 d transitions in Tb_(3+) ions was additionally observed in the photoluminescence excitation spectra of Gd~(3)Ga~(5)O~(12): Tb_(3+) microceramics. Emission of Tb_(3+) ions under X-ray and UV excitations is presented by two groups of sharp lines which correspond to _(5)D~(3) and _(5)D~(4)?→?_(7)F~(j) transitions of Tb_(3+) ions with the most intense line at 546?nm (_(5)D~(4)?→?_(7)F~(5)). It was established that the increasing of PEG content leads to the decreasing of the X-ray and photoluminescence emission intensities.