Fluorescence spectroscopy and emission lifetimes of Er3+ in ErxSc3−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.