Synthesis, characterisation, luminescence and defect centres in solution combustion synthesised CaZrO3:Tb3+ phosphor

• Published in: Journal of luminescence Vol. 132; no. 8; pp. 2036 - 2042
• Main Authors: Singh, Vijay, Watanabe, S., Gundu Rao, T.K., Al-Shamery, Katharina, Haase, Markus, Jho, Young-Dahl
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2012; Elsevier
• Subjects: Combustion; Combustion synthesis; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Defect annealing; Defect centres; Defects; Electron paramagnetic resonance; Electron paramagnetic resonance and relaxation; Emission analysis; Exact sciences and technology; Luminescence; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other luminescence and radiative recombination; Other solid inorganic materials; Phosphors; Photoluminescence; Physics; Tb3; Thermoluminescence; Combustion; Defect centres; Tb3; Phosphors; Photoluminescence; Terbium additions; Radiation effects; Combustion synthesis; F centers; Doping; XRD; Calcium Zirconates; Tb; Defects; g-factor; Gamma irradiation; Electron paramagnetic resonance; Fourier-transformed infrared spectrometry; Thermoluminescence
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2012.03.027

Tb3+ doped CaZrO3 has been prepared by an easy solution combustion synthesis method. The combustion derived powder was investigated by X-ray diffraction, Fourier-transform infrared spectrometry and scanning electron microscopy techniques. A room temperature photoluminescence study showed that the phosphors can be efficiently excited by 251nm light with a weak emission in the blue and orange region and a strong emission in green light region. CaZrO3:Tb3+ exhibits three thermoluminescence (TL) glow peaks at 126°C, 200°C and 480°C. Electron Spin Resonance (ESR) studies were carried out to study the defect centres induced in the phosphor by gamma irradiation and also to identify the centres responsible for the TL peaks. The room temperature ESR spectrum of irradiated phosphor appears to be a superposition of two distinct centres. One of the centres (centre I) with principal g-value 2.0233 is identified as an O− ion. Centre II with an axial symmetric g-tensor with principal values g=1.9986 and g˔=2.0023 is assigned to an F+ centre (singly ionised oxygen vacancy). An additional defect centre is observed during thermal annealing experiments and this centre (assigned to F+ centre) seems to originate from an F centre (oxygen vacancy with two electrons). The F centre and also the F+ centre appear to correlate with the observed high temperature TL peak in CaZrO3:Tb3+ phosphor. ► Powder phosphor of CaZrO3:Tb3+ was prepared by an easy solution combustion synthesis method. ► The phosphor exhibits a bright green emission at 545nm (5D4→7F5) of the Tb3+ ion. ► Electron Spin Resonance studies have been carried out to identify the defect centres responsible for the observed thermoluminescence peaks.