Niobium-oxygen octahedra and oxygen interstitial defect emissions in calcium niobate matrix and its color manipulation via doping Pr3

The luminescent properties of Ca2Nb2O7 matrix and Ca2Nb2O7: Pr3+ were studied in this work. In addition to the emission band from NbO6 octahedra, the orange-red emission aroused by oxygen interstitial defects was observed in Ca2Nb2O7. When Pr3+ was introduced, both of the matrix emission and the characteristic Pr3+ luminescence could appear simultaneously under suitable excitation wavelength. By further adjusting the doping concentration, color manipulation from blue-green to pink and red could be realized in Ca2Nb2O7: Pr3+. In particular, a warm white light could be achieved when doping 0.1% Pr3+. Based on the luminescent results, the underlying mechanisms were discussed and proposed. The color manipulation results suggest that Ca2Nb2O7: Pr3+ is promising for various fields related to lighting, displaying, and imaging.