Luminescence studies and EPR investigation of solution combustion derived Eu doped ZnO

• ZnO:Eu nanopowders have been synthesized by simple low cost SCS method.
• SEM and TEM images reveal quasi-hexagonal morphology of the samples.
• ZnO:Eu nanopowders show PL peaks corresponding to both Eu2+ and Eu3+ ions.
• EPR spectrum exhibits a broad resonance signal attributed to Eu2+ ions.
• EPR and TL studies reveal native defects. The trap parameters are discussed.

ZnO:Eu (0.1 mol%) nanopowders have been synthesized by auto ignition based low temperature solution combustion method. Powder X-ray diffraction (PXRD) patterns confirm the nanosized particles which exhibit hexagonal wurtzite structure. The crystallite size estimated from Scherrer’s formula was found to be in the range 35–39 nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies reveal particles are agglomerated with quasi-hexagonal morphology. A blue shift of absorption edge with increase in band gap is observed for Eu doped ZnO samples. Upon 254 nm excitation, ZnO:Eu nanopowders show peaks in regions blue (420–484 nm), green (528 nm) and red (600 nm) which corresponds to both Eu2+ and Eu3+ ions. The electron paramagnetic resonance (EPR) spectrum exhibits a broad resonance signal at g = 4.195 which is attributed to Eu2+ ions. Further, EPR and thermoluminescence (TL) studies reveal presence of native defects in this phosphor. Using TL glow peaks the trap parameters have been evaluated and discussed.

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