Affiliation: | aDepartment of Physics, Baptist University of Hong Kong, Waterloo Road, Kowloon, Hong Kong SAR, PR China bDepartment of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, PR China |
Abstract: | A new 1.75 μm infrared emission transition of Y2O3:Er3+ is assigned to the 4S3/2 → 4I9/2 transition of Er3+ ions situated at the C2 sites of cubic RE2O3 (RE = Y, Gd, Lu). The intensities of features in the 1.54 μm 4I15/2–4I13/2 absorption transition due to Er3+ at S6 and C2 sites are consistent with the site occupation ratio and the relative magnetic dipole–electric dipole intensity contributions of Er3+ at the different sites. The 1.54 μm emission lines are predominantly from Er3+ ions at C2 sites. The different behaviours of the emission intensities 1.75 and 1.54 μm groups with change in Er3+ dopant ion concentration, preparation technique, Yb3+ co-doping, temperature change and different excitation line are rationalized. |