Bluish white emitting Sr2CeO4 and red emitting Sr2CeO4:Eu3+ nanoparticles: optimization of synthesis parameters, characterization, energy transfer and photoluminescence

Abstract

Blue-white light emitting Sr₂CeO₄ and red emitting Sr₂CeO₄:Eu³⁺ nanoparticles were prepared using a polymeric precursor route. The synthetic conditions were optimized to achieve a suitable calcination temperature and heat treatment time. The systems were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The concentration of dopant ions was optimized to maximise the PL intensity. The effect of concentration on excitation, emission and lifetime spectroscopy was investigated in detail. The critical energy-transfer distance for the Eu³⁺ ions was evaluated and based on this, the quenching mechanism was verified to be a multipole–multipole interaction. The Judd–Ofelt parameter and other photophysical properties were evaluated for all samples. The observed trend in the J–O parameter was correlated with the characteristics of the chemical environments around the Eu³⁺ ions, with respect to the composition of the europium ion.