p-Type PbTe is an outstanding high temperature thermoelectric material with zT of 2 at high temperatures due to its complex band structure which leads to high valley degeneracy. Lead-free SnTe has a similar electronic band structure, which suggests that it may also be a good thermoelectric material. However, stoichiometric SnTe is a strongly p-type semiconductor with a carrier concentration of ...

12 We discuss the use of resonant photoemission in the study of rare earth/transition metal perovskites and perovskite-related structures. We illustrate its application to the assignment of the RE and TM valence band density of states in Nd2Ni1−xCuxO4 and REBaCo2O5+δ. In both cases, the relative positions of the 4f and 3d contributions within the valence band density of states (DOS) relative to...

Using the technique of tight-binding electron-ion dynamics, we have calculated the response of crystalline GaAs when a femtosecond laser pulse excites 1− 20% of the valence electrons. Above a threshold fluence, which corresponds to promotion of about 12% of the valence electrons to the conduction band, the lattice is destabilized and the band gap collapses to zero. This result supports the conc...

The standard polaron band model of doped organic semiconductors predicts that density-of-states shift into the π-π* gap to give a partially filled polaron band that pins the Fermi level. This picture neglects both Madelung and Hubbard interactions. Here we show using ultrahigh workfunction hole-doped model triarylamine-fluorene copolymers that Hubbard interaction strongly splits the singly-occu...

In this paper we analytically study the effects of the lattice discreteness on the electron band in the SSH model. We propose a modified version of the TLM model which is derived from the SSH model using a continuum approximation. When a soliton is induced in the electron-lattice system, the electron scattering states both at the bottom of the valence band and the top of the conduction band are...

We identify contributions to the valence band of the nanosized BaFe12−2xCoxTixO19 barium ferrite particles, from the cobalt and titanium dopants. Resonant photoemission results show that cobalt and titanium dopants strongly hybridize with the barium ferrite matrix. Fano resonances are identifi ed in the valence band region, at the Ba (5s), Ti (3p) and Co (3p) thresholds, and there are signifi c...

Spin-resolved photoemission spectra of 6-, 9-, and 13-eV satellites of the ferromagnetic Ni valence band are reported. The spin polarization of the valence-band satellites and their photon energy dependence are interpreted by the multiplet configuration of 3d and 3d final states. This implies the localization of a photoexcited final state reflecting the strong electron correlation in Ni. @S0163...

A sample of the β-Ga2O3/wurtzite GaN heterostructure has been grown by dry thermal oxidation of GaN on a sapphire substrate. X-ray diffraction measurements show that the β-Ga2O3 layer was formed epitaxially on GaN. The valence band offset of the β-Ga2O3/wurtzite GaN heterostructure is measured by X-ray photoelectron spectroscopy. It is demonstrated that the valence band of the β-Ga2O3/GaN struc...

We identify contributions to the valence band of the nanosized BaFe12−2xCoxTixO19 barium ferrite particles, from the cobalt and titanium dopants. Resonant photoemission results show that cobalt and titanium dopants strongly hybridize with the barium ferrite matrix. Fano resonances are identifi ed in the valence band region, at the Ba (5s), Ti (3p) and Co (3p) thresholds, and there are signifi c...

The electronic structure of potassium-doped La@C82 has been studied with synchrotron-radiation photoelectron spectroscopy. Ultraviolet photoemission measurements indicate evolution of the valence-band states of La@C82 with increasing potassium content, but KxLa@C82 remains semiconducting for all x between 0 and 6, with a band gap of at least 0.4 eV, in contrast to K-doped C60. The valence-band ...