Room temperature photoluminescence in crystalline/amorphous Er-doped Cd2V2O7

Er3+ ions were introduced into a new type of oxide matrixes prepared with different proportions of CdO and V2O5. The source of Er3+ employed was Er(NO3)3·5H2O, which yielded an Er3+ concentration of ∼1 at%. Depending on the reactants proportions, the samples resulted in crystalline or amorphous structures. X-ray diffraction indicated that the crystalline samples were constituted by polycrystalline Cd2V2O7, in agreement with Raman spectroscopy measurements. Depending on the proportions of the component oxides, the band gap changed in the 2.49–1.77 eV energy range, as determined through photoacoustic spectroscopy. From photoluminescence spectra, the following electronic transitions of Er3+ were observed in both types of samples: {2H11/2, 4S3/2, 4F9/2, 4I9/2}→4I15/2 and 4S3/2→4I13/2. In the case of crystalline samples manifolds, originating from the Stark effect, were measured for the {2H11/2, 4S3/2, 4F9/2}→4I15/2 and 4S3/2→4I13/2 transitions.