Band-structure effects in the excitation-energy dependence of SiL2,3x-ray-emission spectra

Soft X-Ray Emission Studies of the Electronic Structure in Silicon Nanoclusters

“…In fact the spectra looks more like what is observed for amorphous silicon [10]. Yet x-ray diffraction and TEM studies of these clusters have shown they are crystalline in nature [4].…”

“…The SXF spectra were excited at 100 eV for the bulk silicon and the 1.6 nm clusters and 100.2 eV for the 2nm clusters. The bulk silicon SXF spectrum exhibits the three characteristic peaks, one at 89 eV associated with low-lying 3s states, another due to a density of states (DOS) maximum at 91.5 eV with strong s-p hybridization and a high DOS at 96 eV which is dominated by p-type states [9][10][11]. The intense peak at approximately 100 eV is due to reflected light from the undulator beamline into the spectrometer.…”

Soft X-ray fluorescence: A multifaceted window to view the electronic structure of matter

“…Enhancement in the emission is clearly visible for these symmetry directions. Similarly, other variations in the emission spectrum, such as' the changing ratio of peaks A and B, may be explained in the context of this model [10]. The emission spectrum from the valence band gradually resembles the one produced by electron-beam excitation, as the photon excitation energy increases.…”

“…In order to confirm the proposed theoretical explanation of threshold effects in Si and C in terms of a k-conserving inelastic process, our group conducted measurements at the NSLS on amorphous and crystalline silicon [10], using a monochromator with a narrow 0.4 eV bandpass. The results are shown in Fig.…”

“…With photon excitation near threshold, however, many recent studies have demonstrated that several distinct physical processes couple excitation and emission. Measurements on molecular gases [7] and crystalline samples of Si and C [8,9,10] show a strong modulation of spectral features as a function of photon energy. In systems with localized orbitals, the modulations can be understood as resonant excitation to localized excited states.…”