Photoluminescence properties of sesquioxide doped ceria synthesized by modified sol–gel route

Highly crystalline and porous sesquioxide (Sm2O3, La2O3) doped ceria with different molar ratio is successfully synthesized by a simple modified sol–gel route. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) are used to investigate their phase, microstructure and composition. XRD analysis confirmed the formation of highly crystalline cubic fluorite phase in all samples. The Raman spectroscopy revealed a single triple degenerated F2g mode as the attestation of the oxygen vacancy in the doped and undoped samples. Strong photoluminescence lines due to interconfigurational transition and vacancy mediated transition were observed in doped CeO2. The oxygen vacancy induced luminescence of CeO2 was strongly enhanced due to La doping. The effect of rare earth dopant on the photoluminescence properties has been studied in details.