Impact of Tb3+ ion concentration on the morphology, structure and photoluminescence of Gd2O2SO4:Tb3+ phosphor obtained using thermal decomposition of sulfate hydrate

• Published in: Luminescence (Chichester, England) England), 2020-12, Vol.35 (8), p.1254-1263
• Main Authors: Rodrigues, R.V., Marciniak, Ł., Khan, L.U., Muri, E.J.B., Cruz, P.C.M., Matos, J.R., Strȩk, W., Marins, A.A.L.
• Format: Article
• Language: English
• Subjects: Analytical methods; Decomposition; Diffraction patterns; Display devices; Dopants; Emissions; Emissions control; Field emission; Fourier analysis; Fourier transforms; Gadolinium; Gd2O2SO4:Tb3; Hydrates; Infrared spectroscopy; Ion concentration; Luminescence; Magnetic permeability; Magnetic susceptibility; Material properties; Morphology; oxysulfate; Particle size distribution; Phosphors; Photoluminescence; Photons; rare earth; Sulfates; Terbium; Thermal decomposition; Thermal degradation; Thermal stability
• ISSN: 1522-7235; 1522-7243
• DOI: 10.1002/bio.3886

Gadolinium oxysulfate doped with terbium (Gd2O2SO4:Tb3+; 0.1, 1.0, and 10.0 mol%) materials were obtained using thermal decomposition from sulfate hydrate under a dynamic air atmosphere and between 1320–1400 K. The materials were characterized using Fourier transform infrared spectroscopy, thermogravimetric/derivative thermogravimetric investigations and X‐ray powder diffraction patterns. The Tb2O2SO4 compound was obtained at 1300 K and was used to compare thermal stability and photoluminescence behaviour with that of Gd2O2SO4:Tb3+ (0.1, 1.0, and 10.0 mol%). Magnetic susceptibility measurements indicated the presence of 15% Tb4+ phases within Tb2O2SO4. The materials were excited at 377 nm and displayed green narrow lines with the strongest emission peak at 545.5 nm due to the 5D4→7F5 transition of Tb3+ ions. Brightness of terbium‐activated gadolinium oxysulfate phosphors was enhanced with increase in the concentration of Tb3+. Detailed analysis of spectroscopic properties of materials under investigations revealed efficient Gd2O2SO4 to Tb3+ and Tb3+ to Tb3+ energy transfers. Increase in dopant concentration led to the enhancement of 5D4→7FJ emission intensity and reduction of 5D3→7FJ emission intensity via cross‐relaxation mechanisms. Distribution of particle size was increased by controlling dopant concentration in the host lattice. Obtained results confirmed that these materials could be applied potentially in field emission display devices and light‐emitting diodes.