Orientation-dependent C60 electronic structures revealed by photoemission

TL;DR

This study reveals how the orientation of C60 molecules on different substrates significantly influences their electronic structures, as shown by angle-resolved photoemission and supported by new band-structure calculations.

Contribution

It demonstrates the critical impact of molecular orientation on the electronic properties of C60 monolayers, combining experimental photoemission data with theoretical calculations.

Findings

Fermi surface symmetry varies with substrate orientation

Bandwidth and dispersion curvature depend on molecular orientation

Orientation is a key factor in fulleride electronic structure

Abstract

We observe, with angle-resolved photoemission, a dramatic change in the electronic structure of two C60 monolayers, deposited respectively on Ag (111) and (100) substrates, and similarly doped with potassium to half-filling of the C60 lowest unoccupied molecular orbital. The Fermi surface symmetry, the bandwidth, and the curvature of the dispersion at Gamma point are different. Orientations of the C60 molecules on the two substrates are known to be the main structural difference between the two monolayers, and we present new band-structure calculations for some of these orientations. We conclude that orientations play a key role in the electronic structure of fullerides.