Size confinement effect in graphene grown on 6H-SiC (0001) substrate

We have observed the energy structure in the density of occupied states of graphene grown on n-type 6H-SiC (0001). The structure revealed with photoelectron spectroscopy is described by creation of the quantum well states whose number and the energy position (E1 = 0.3 eV, E2 = 1.2 eV, E3 = 2.6 eV ) coincide with the calculated ones for deep (V = 2.9 eV) and narrow (d = 2.15 A) quantum well formed by potential relief of the valence bands in the structure graphene/n-SiC. We believe that the quantum well states should be formed also in graphene on dielectric and in suspended graphene.Comment: 7 pages, 4 figure

The p-n junction formation effect of an Ar

The electronic structure of the well-defined n-GaAs (100) near-surface layer irradiated by an $\text{Ar}^{+}$ ion beam of the keV energy range has been studied by synchrotron-based photoelectron spectroscopy. Conversion of the conductivity type from n into p has been revealed in the irradiated layer several nm thick, thus resulting in the $p\text{-}n$ junction formation. The effect manifests itself in adjoining the valence band edge to the Fermi level. Transformation of the conductivity type has been shown to be caused by Ga-antisite point defects generated by mechanical impact of inert argon atoms diffusing away after implantation. The possibility of local formation of a $p\text{-}n$ nanojunction by $\text{Ar}^{+}$ ion beam within the beam spot has been demonstrated

Contribution of different channels to the doubly differential cross sections for ejection of electrons in ³He²⁺–H₂ collisions

<p><strong>Figure 5.</strong> Contribution of different channels to the doubly differential cross sections for ejection of electrons in ³He²⁺–H₂ collisions. The cross sections for DI, QA and their sum (total) are shown.</p> <p><strong>Abstract</strong></p> <p>Energy spectra of electrons ejected into ³He²⁺–H₂ collisions have been measured in the incident ion energy range 6–30 keV. Parameters of the quasimolecule formed during the collision are determined. The dominant role of the channel (2a')² → 1a'3a' → 1a' + <em>e</em> in the production of electrons at keV ion energies has been revealed. The structure associated with autoionization transitions in the projectile helium atoms shows enormously large broadening and shift to lower energies.</p

Energy spectra of electrons ejected in He²⁺–H₂ collisions

<p><strong>Figure 1.</strong> Energy spectra of electrons ejected in He²⁺–H₂ collisions.</p> <p><strong>Abstract</strong></p> <p>Energy spectra of electrons ejected into ³He²⁺–H₂ collisions have been measured in the incident ion energy range 6–30 keV. Parameters of the quasimolecule formed during the collision are determined. The dominant role of the channel (2a')² → 1a'3a' → 1a' + <em>e</em> in the production of electrons at keV ion energies has been revealed. The structure associated with autoionization transitions in the projectile helium atoms shows enormously large broadening and shift to lower energies.</p