Experimental and theoretical study of the effect of bombardment with Ar+ ions on the spectrum of valence electrons of a Si (111) single crystal

Yokub Ergashov,Nebodir Nurmatov,Golib Otamurodov,Boltaxodja Umirzakov,V.A Golenishchev-Kutuzov

doi:10.1051/e3sconf/202128801013

Yokub Ergashov, Nebodir Nurmatov + Show 3 more

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https://doi.org/10.1051/e3sconf/202128801013

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The paper studies the effect of disordering of the surface layers on the electronic and optical properties of single-crystal silicon.An analysis of the photoelectron spectra shows that with complete amorphization of the surface density, the condition of Si valence electrons of changes significantly. In particular, the positions of the main maximum of the electrons of the valence band of Si (111) shift by ~ 0.4 eV towards higher binding energies and the band gap Eg increases by 0.1-0.15 eV. The energy of a valence electron in amorphized silicon, which at low impurity concentrations, i.e. at low bombardment doses (D <1015 cm–2), the potential Mkk and, therefore, the shift of the maximum of the density of states vary linearly with respect to concentration. At high impurity concentrations (at doses D> 1015 cm–2), corresponding to the transition to amorphous silicon, the concentration dependence of Mkk is very weak. Therefore, upon amorphization, the peak A of the density of states of the silicon valence band under consideration is shifted to the region of lower electron binding energies. The theoretical substantiation of the obtained experimental results is given.

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Experimental and theoretical studies presented in [1-5] have shown that atom deposition, ion implantation, laser irradiation and other effects in different crystals lead to a sharp change in the electronic and crystal structure of their surface region, and these changes are mainly due to the formation of nanoscale structures, changes in the stoichiometric composition and phase structure of the near-surface layer
Any change in the physicochemical state of the surface first of all leads to a change in the density of state of valence electrons, which is well reflected in the experimental spectrum of photoelectrons: change in the intensity, shape and energy position of existing peaks or their disappearance and the appearance of new peaks [6,8-22]
The Ar+ bombardment was conducted perpendicular to the surface

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Introduction

Experimental and theoretical studies presented in [1-5] have shown that atom deposition, ion implantation, laser irradiation and other effects in different crystals lead to a sharp change in the electronic and crystal structure of their surface region, and these changes are mainly due to the formation of nanoscale structures, changes in the stoichiometric composition and phase structure of the near-surface layer. Any change in the physicochemical state of the surface (the appearance of vacancies and interstitial atoms, the introduction or substitution of an implanted impurity, the appearance of active centers, disordering, the formation of compounds, etc.) first of all leads to a change in the density of state of valence electrons, which is well reflected in the experimental spectrum of photoelectrons: change in the intensity, shape and energy position of existing peaks or their disappearance and the appearance of new peaks [6,8-22] The study of these changes is very important in the development of multilayer nanofilm metal-dielectricsemiconductor (MDS) and semiconductor dielectric semiconductor (SDS) structures, electronic and optical devices, including solar cells. The given setup was based on a universal ultrahighvacuum facility (Chernogolovka, Moscow oblast) [1921]

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