Upconversion Luminescence Properties of Y₂O₃:Yb, Er and Y₂O₂S:Yb, Er Nanoparticles Prepared by Complex Precipitation

Figure 1

XRD patterns of (a) Y₂O₃:Yb, Er and (b) Y₂O₂S:Yb, Er nanocrystals calcined at 900°C ( and denote the characteristic peaks corresponding to Y₂O₃ and Y₂O₂S, resp.).