Atomic-scale and optical investigation of nanostructured Er disilicates in silica

The optical and structural properties of Er-doped Silicon oxide based thin films elaborated by RF magnetron sputtering were investigated as a function of annealing treatment. Atom Probe Tomography and Transmission electron microscopy were used to analyze the position of rare-earth ions as well as the phase separation occurring in the layer in order to provide a complete picture of the nanostructure. The emission properties of Er3+ ions were investigated using cathodoluminescence (CL) spectroscopy. The high doping level of Er ions in silicon oxide matrix leads to a phase decomposition of pure SiO2 and Er2Si2O7 phases with a nanostructure which is influenced by the annealing treatment. It results on different emission intensities in ultraviolet or infrared ranges. The relationship between the nanostructuration observed and the optical properties is discussed in regards of annealing treatment.