We report on the fabrication and characterization of ultrathin self-assembl
ed fullerene films. Using a carboxy-functionalized fullerene and poly(ethyl
en imine) we prepare fullerene films with the technique of layer-by-layer a
dsorption. Our structures exhibit a modulated electron density as evidenced
by the observation of a quasi-Bragg reflection in X-ray reflectivity studi
es. This relatively high degree of order is attributed to the formation of
hydrogen bonds.