Direct determination of the valence‐band offsets at Ga0.47In0.53As/InP and InP/Ga0.47In0.53As heterostructures by ultraviolet photoemission spectroscopy

ABSTRACTWe have developed a novel experimental technique for accurately determining band offsets in semiconductor quantum wells (QW). It is based on the fact that the ground state heavy- hole (HH) band energy is more sensitive to the depth of the valence band well than the light-hole (LH) band energy. Further, it is well known that as a function of the well width, Lz, the energy difference between the LH and HH excitons in a lattice matched, unstrained QW system experiences a maximum. Calculations show that the position, and more importantly, the magnitude of this maximum is a sensitive function of the valence band offset, Qy, which determines the depth of the valence band well. By fitting experimentally measured LH-HH splittings as a function of Lz, an accurate determination of band offsets can be derived. We further reduce the experimental uncertainty by plotting LH-HH as a function of HH energy (which is a function of Lz ) rather than Lz itself, since then all of the relevant parameters can be precisely determined from absorption spectroscopy alone. Using this technique, we have derived the conduction band offsets for several material systems and, where a consensus has developed, have obtained values in good agreement with other determinations.

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Determination of the valence band edge of Fe oxide nanoparticles dispersed in aqueous solution through resonant photoelectron spectroscopy from a liquid microjet

Nanoscale Advances ◽

10.1039/d1na00275a ◽

2021 ◽

Author(s):

Giorgia Olivieri ◽

Gregor Kladnik ◽

Dean Cvetko ◽

Matthew A. Brown

Keyword(s):

Aqueous Solution ◽

Electronic Structure ◽

Valence Band ◽

Photoelectron Spectroscopy ◽

Band Edge ◽

Photoemission Spectroscopy ◽

Oxide Nanoparticles ◽

Valence Band Edge ◽

Resonant Photoemission

The electronic structure of hydrated nanoparticles can be unveiled by coupling a liquid microjet with a resonant photoemission spectroscopy.

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Valence band ultraviolet photoemission spectroscopy of Dy/W(100)

Vacuum ◽

10.1016/s0042-207x(02)00227-0 ◽

2002 ◽

Vol 67 (3-4) ◽

pp. 429-433 ◽

Cited By ~ 11

Author(s):

N Moslemzadeh ◽

S.D Barrett ◽

V.R Dhanak ◽

G Miller

Keyword(s):

Valence Band ◽

Photoemission Spectroscopy ◽

Ultraviolet Photoemission Spectroscopy

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BBonding in minerals: the application of PAX (photoelectron and X-ray) spectroscopy to the direct determination of electronic structure

Mineralogical Magazine ◽

10.1180/minmag.1989.053.370.03 ◽

1989 ◽

Vol 53 (370) ◽

pp. 153-164 ◽

Cited By ~ 8

Author(s):

David S. Urch

Keyword(s):

Electronic Structure ◽

Valence Band ◽

Photoelectron Spectroscopy ◽

Direct Determination ◽

Energy Scale ◽

X Ray ◽

Electron Transitions ◽

Dipole Selection Rule ◽

The Individual

AbstractX-ray photoelectron spectroscopy can be used to measure the ionization energies of electrons in both valence band and core orbitals. As core vacancies are the initial states for X-ray emission, a knowledge of their energies for all atoms in a mineral enables all the X-ray spectra to be placed on a common energy scale. X-ray spectra are atom specific and are governed by the dipole selection rule. Thus the individual bonding roles of the different atoms are revealed by the fine structure of valence X-ray peaks (i.e. peaks which result from electron transitions between valence band orbitals and core vacancies). The juxtaposition of such spectra enables the composition of the molecular orbitals that make up the chemical bonds of a mineral to be determined.Examples of this approach to the direct determination of electronic structure are given for silica, forsterite, brucite, and pyrite. Multi-electron effects and developments involving anisotropic X-ray emission from single crystals are also discussed.

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