Energy-resolved momentum densities for the valence band of a nanoscale Si single crystal

Abstract

We have measured the energy-and momentum-resolved band structure, and ground state of occupation of the bands, for a crystalline silicon sample along the 100 and 110 directions. Band structures were determined directly by the technique of electron momentum spectroscopy (EMS) for a self-supporting Si membrane with a thickness of approximately 7 nm. We compare our experimental results with ab initio calculations for bulk crystalline silicon performed within the linear muffin tin orbital approximation. Qualitative agreement is seen between experiment and theory for the main valence band peak. Additional intensity is observed in the measurement on either side of the main peak and is attributed mainly to multiple-scattering events. Satellite structure could also be present in these additional features, although there is no direct evidence for this.

The electronic structure of Be and BeO: benchmark EMS measurements and LCAO calculations

“…Transmission EMS on solid samples is generally difficult, since measurements are subject to multiple scattering of the electrons within the sample [3,4]. However, the signal-to-noise ratio is vastly improved when the solid samples are thin (~100 Å), or when they are composed of light elements.…”

Spectral properties of quasiparticles in silicon: A test of many-body theory

“…The use of such high energies for the incident and emitted electrons reduces greatly the multiple scattering effects, which plagued earlier measurements. 17,18 These high energies have the added advantage that the measurement is relatively bulk sensitive, i.e., it is not strongly affected by surface reconstructions and surface states as is the case for low-energy ARPES measurements. The energies and azimuthal angles of the emitted electrons, detected in coincidence, are measured with electrostatic analyzers fitted with two-dimensional positionsensitive detectors.…”

Measuring the electronic structure of disordered overlayers by electron momentum spectroscopy: the Cu/Si interface

“…These values are consistent with previous findings for the bottom of the band for Cu 8 and Si. 5 For the Si-on-Cu sample, the peak is at an intermediate position indicating that the occupied band width of the reacted layer is inbetween that of Cu and Si. For momenta in the 0.4-0.5 a.u.…”