Valence-band structure ofα-Sn determined by angle-resolved photoemission

We have determined the electronic band structure of {α}-Sn along the {Γ}--X line experimentally through interpretation of photoelectron spectra recorded over a range of photon energies in terms of direct transitions. Our band structure agrees well with calculated bands. We find that problems in band-structure determinations from spectra recorded at low photon energies may be traced to the deviation of the final band from parabolic behavior near zone boundaries; by evaluating band shapes through transitions in higher Brillouin zones we are able to determine these deviations in the final band near {Γ}. This final band is well described by a parabola with an effective mass of m*=0.216mₑₗ.