Observation of highly dispersive bands in pure thin film C${}_{60}$

While long-theorized, the direct observation of multiple highly dispersive C${}_{60}$ valence bands has eluded researchers for more than two decades due to a variety of intrinsic and extrinsic factors. Here we report a realization of multiple highly dispersive (330-520 meV) valence bands in pure thin film C${}_{60}$ on a novel substrate–the three-dimensional topological insulator Bi${}_2$Se${}_3$–through the use of angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations. The effects of this novel substrate reducing C${}_{60}$ rotational disorder are discussed. Our results provide important considerations for past and future band structure studies as well as the increasingly popular C${}_{60}$ electronic device applications, especially those making use of heterostructures.