Electronic structure analysis and properties of Sr2CeO4 grown by sol–gel method

Sr2CeO4 is a very promising material due to its various industrial applications, e.g. for the construction of field emission displays and light emitting diodes. In this work, the phosphor was synthesized by the sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) methods. They proved to be very good structural properties of the material and identified negligible impurities from the technological process. The decomposition of the surface of the nanocrystals was found but this did not decrease the spectral features of the compound. The analysis of the XPS O2p lines revealed contributions of two kinds of bonds: terminal and equatorial ones, in the ratio of 2/4. They are separated by 1.2 eV what is in agreement with the observed absorption spectra. A presence of the decomposed layers may produce asymmetric widening of the emission spectra towards a lower energy.

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► Sr2CeO4 nanopowders were obtained by sol–gel method.
► SEM/EDX imaging and chemical analysis have been done.
► XPS electronic structure was examined and discussed.
► The terminal and equatorial CeO bonds contributions were determined in O2p states.
► The energy gap was estimated by valence band and electrical measurements.