Brillouin-zone-selection effects in graphite photoelectron angular distributions

Experimental and theoretical graphite valence-band photoelectron angular distributions are presented and compared. We observe a zone-selection effect, wherein interference between photoelectron amplitudes from the two atoms in each graphene unit cell cause both σ and π states to appear with different intensity in otherwise equivalent Brillouin zones. To simulate the experimental graphite valence-band photoelectron angular distributions, our simple model includes effects of (1) valence-band wave functions and (2) the relative emission path-length difference, from the atoms in each unit cell to one’s detector (which is determined by the experimental geometry).