Fluorescence spectroscopy and emission lifetimes of Er³⁺ in Er_xSc_3-xN@C₈₀ (x=1-3)

We have measured the spectra and lifetimes of the emission near 1.5 μm from Er3+ ions within the recently discovered endohedral metallofullerene family ErxSc3-xN@C80. These molecules consist of a highly symmetric C80 (Ih) fullerene cage containing a triangular tri-metal nitride group. The measured emission decay lifetimes, the first reported for ions in endohedral fullerenes, are all in the range 1.1-1.6 s, showing that for the present species the quantum efficiency for emission is ~10-4. High-resolution emission spectra at 1.6 K show sharp features that differ for the Er1, Er2 and Er3 species and provide information about the structural differences among them. © 2001 Elsevier Science B.V.