Eur. Phys. J. B 1, 11-17 (1998)
https://doi.org/10.1007/s100510050147

The electronic structure of (C₅₉N)₂ from high energy spectroscopy

¹ Institute for Solid State and Materials Research (IFW) Dresden, 01171 Dresden, Germany
² Institute for Polymers and Organic Solids, Department of Chemistry and Materials, University of California, Santa Barbara, California 93106, USA

Corresponding author: ^a haffner@ifw-dresden.de

Received: 25 August 1997
Revised: 22 September 1997
Accepted: 16 October 1997
Published online: 15 January 1998

Abstract

We report the results of a detailed study of the occupied and unoccupied electronic structure of dimers of the new heterofullerene C₅₉N by means of photoemission and electron energy-loss spectroscopy. A close similarity is found between the electronic structures of pristine (C₅₉N)₂ and C₆₀ with an additional broadening of the spectra in the former due to the distortion of the fullerene cage caused both by dimerization and the chemical substitution. Both the occupied and unoccupied electronic states, as well as the interband transitions between them, attest to the high degree of molecular character retained in the solid state. Comparison of the shake-up structures in the C_1s and N1_s X-ray photoemission spectra confirm that the highest lying occupied states in the heterofullerene have a strong degree of N character, whereas the lowest lying unoccupied states have mainly C character. We also present the optical conductivity of the heterofullerene (derived from the loss function), which shows an optical gap of 1.4 eV, some 0.4 eV smaller than that of C₆₀.