| Abstract |
Details of the synthesis, spectroscopic, optical, morphological and structural characterisation of silica microspheres activated by Era(3+) ions produced by the sol-gel route are presented. Acetic acid is used to catalyse the hydrolysis and condensation of tetraethyl orthosilicate in the presence of ErCl3. SEM and TEM images are used to determine the dimension of the spheres and demonstrate the high quality of their surfaces. Photoluminescence measurements, both on single spheres and on pressed KBr pellets, containing 5\% Er3+-doped silica spheres, confirm the incorporation of Er3+ ions into the silica matrix. The measured lifetime is 13.7 ms, relative to the I-4(13/2) metastable state corresponding to a system quantum efficiency of 76\%. |
