J. Szuber - Academia.edu (original) (raw)
Papers by J. Szuber
Electrochimica Acta, 2012
The work describes the formation of poly(3,4-ethylenedioxythiophene) (PEDOT) brushes attached to ... more The work describes the formation of poly(3,4-ethylenedioxythiophene) (PEDOT) brushes attached to thienyl-modified glassy carbon surface (GC) via surface-initiated electrochemical polymerization. The initial modification of the GC electrode was performed by using of three different thienyl-derivatives of aniline that were first converted to the form of diazonium salts. These salts were then electrochemically reduced creating the organic monolayer covalently bound to GC. The surface layer was investigated electrochemically and identified using XPS. The structural conjugation of the resulting monolayer made it possible to initiate the electrochemical polymerization of EDOT from the modified surface. The polymeric structure formed on the thienyl-modified surface reveals a better redox peak separation as compared to the classical polymer film on a bare electrode that can be assigned to its more ordered and uniform structure.
Electron Technology, 2000
Applied Surface Science, 2017
Acta Physica Polonica A, 1984
Etude de la distribution des etats electroniques de surface dans la bande interdite de la surface... more Etude de la distribution des etats electroniques de surface dans la bande interdite de la surface (100) de GaAs type n recuit sous ultravide entre 500 et 800 K. Observation d'une bande d'etats de surface dans la bande interdite en dessous du niveau de Fermi. Correlations interessantes avec des etudes recentes de rendement photoelectrique
A control and characterisation of the surface/interface state density, NSS(E), is the key problem... more A control and characterisation of the surface/interface state density, NSS(E), is the key problem of III-V semiconductor technology. The powerful, contactless, and non-destructive technique for an assessment of NSS(E) for both free and covered surfaces is the photoluminescence surface state spectroscopy (PLS), which was developed by the group of Hasegawa [1]. In the PLS method, the band-edge photoluminescence (PL) efficiency YPL, i.e. the PL intensity divided by the excitation light intensity Φ, is measured as a function of Φ at room temperature. Then, the obtained YPL−Φ spectrum is compared with the theoretical curves rigorously calculated using a numerical simulator of photo-electronic phenomena in a semiconductor, in order to determine NSS(E) [1-3]. The simulator takes account of all possible processes of recombination in a bulk: band-to-band radiative transitions, Shockley-Read-Hall (SRH) recombination through deep levels, and Auger recombination, as well non-radiative recombina...
In this paper, the XPS study of SnO thin films deposited by the L-CVD technique are presented. The... more In this paper, the XPS study of SnO thin films deposited by the L-CVD technique are presented. The influence of exposition 2 of the as-deposited samples to oxygen O and hydrogen H on their stoichiometry was determined. Moreover, on the basis of 22 detailed shape analysis of the Sn3d and O1s XPS peaks, the chemical shift of binding energy corresponding to the change of 5 2 sample stoichiometry was separated from a shift of the binding energy corresponding to the change of interface Fermi levelposition E Fv E in the band gap, using a new procedure of deconvolution of the core level XPS peaks. The shift of the Sn3d5 2 peak by approximately 0.5 eV towards the lower binding energy after highest H exposure was interpreted as a true chemical 2 shift due to an increase of Sn 2 component, whereas the shift of Sn3d peak and O1s peak after highest O exposure by 5 22 approximately 0.5 eV towards the lower binding energy was interpreted as a result of the shift of the interface Fermi levelposition...
![Research paper thumbnail of Retraction notice to “Comparative analysis of physico-chemical and gas sensing characteristics of two different forms of SnO2 films [Appl. Surf. Sci. 401 (2014) 27–31]](https://attachments.academia-assets.com/90579332/thumbnails/1.jpg)
](Applied Surface Science, 2018
Vacuum, 1999
In this paper a selfconstructed unipolar mass filter is presented together with a new method to d... more In this paper a selfconstructed unipolar mass filter is presented together with a new method to determine the partial pressures of gases with near atomic mass number desorbing from the surfaces during surface chemical reactions. It mainly uses the dependence of the efficiency of gas ionisation on the ionisation energy of electrons. Using the proposed procedure, the relative contents of methane and atomic oxygen observed during the cleaning of native oxide covered GaAs (1 0 0) surface by atomic hydrogen were estimated as 0.
Studies in Surface Science and Catalysis, 1985
Journal of Electron Spectroscopy and Related Phenomena, 1984
Photoemission yield spectroscopy (PYS) together with Auger electron spectroscopy (AES) have been ... more Photoemission yield spectroscopy (PYS) together with Auger electron spectroscopy (AES) have been used in an investigation of the electronic properties of the NiO(100) surface, thermally cleaned in ultrahigh vacuum (UHV). The work function and ionization energy were determined. The origin of the filled electronic states band localized below the Fermi level, EF, is briefly discussed.
ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA, 2014
Applied Surface Science, 2012
This work presents the results of systematic X-ray photoelectron spectroscopy (XPS) and photoemis... more This work presents the results of systematic X-ray photoelectron spectroscopy (XPS) and photoemission yield spectroscopy (PYS) studies of the surface electronic properties of L-CVD SnO 2 ultrathin films submitted to various technological treatments. The interface Fermi level position in the band gap E F-E v has been determined from XPS analysis of the Sn3d 5/2 binding energy position. Such value of the Fermi level position was in a good agreement with the value estimated from the offset of XPS valence band. The variation of interface Fermi level position, after the various technological treatments, has been compared to the change of work function obtained by PYS. Valence band XPS spectra and PYS spectra point to the presence of two different bands of filled electronic states of the L-CVD SnO 2 thin films. The first one was localized in the upper part of valence band at the surface at about 6.0 eV below the Fermi level, whereas the second one was localized in the band gap at about 3.0 eV below the Fermi level. The changes of electronic properties of the space charge layer of L-CVD SnO 2 ultrathin films submitted to different technological procedures were assigned to the observed variation of their surface chemistry, including stoichiometry/nonstoichiometry and to the presence of surface carbon contamination.
Surface Science, 2009
The Kelvin method together with the simulations of surface photovoltage has been used to determin... more The Kelvin method together with the simulations of surface photovoltage has been used to determine the surface electronic properties, i.e. the surface band bending (qV S), surface state density (N SS0) and surface fixed charge (Q Fx) of S 2 Cl 2-treated GaAs (100) surfaces. The measured values of surface photovoltage (SPV) do not show saturation at high photon flux densities in contradiction to the simple theory of SPV. This behavior of SPV agrees very well with the rigorous computer simulations and can be explained in terms of the Dember effect. Moreover, the SPV values become insensitive to surface states at moderate photon flux densities. On this basis, the surface band bending of untreated (0.79 eV) and S 2 Cl 2-treated (0.60 eV) GaAs surfaces was determined. The band diagrams summarizing the obtained results proved the influence on the potential variations not only from the ionized surface states and surface fixed charge but also from the surface dipole layer on the S 2 Cl 2-treated GaAs surface. The dipole arises most probably due to the S-Ga bonding on the surface. The presented results offer an alternative explanation for increased PL commonly observed after the sulfidation in the absence of substantial reduction in the band bending.
High-resolution photoemission yield spectroscopy (PYS) has been used to study the electronic prop... more High-resolution photoemission yield spectroscopy (PYS) has been used to study the electronic properties of space charge layer of the real GaAs(100) surface cleaned by atomic hydrogen. The ionization energy, work function and interface Fermi level position were determined as a function of hydrogen dose. Moreover, the evolution of effective density of filled electronic states localized in the band gap and in the upper part of the valence band was observed. Our experiments showed that for the hydrogen dose up to 10 4 L H 2 the contamination etching stage occurs for which the interface Fermi level position E F-E v reaches a value of 1.06 eV. For the higher hydrogen dose at the level 10 5 L H 2 the interface Fermi level position E F-E v reaches a value of 0.75 eV which corresponds to the degradation of GaAs(100) surface that becomes covered by metallic Ga.
Electrochimica Acta, 2012
The work describes the formation of poly(3,4-ethylenedioxythiophene) (PEDOT) brushes attached to ... more The work describes the formation of poly(3,4-ethylenedioxythiophene) (PEDOT) brushes attached to thienyl-modified glassy carbon surface (GC) via surface-initiated electrochemical polymerization. The initial modification of the GC electrode was performed by using of three different thienyl-derivatives of aniline that were first converted to the form of diazonium salts. These salts were then electrochemically reduced creating the organic monolayer covalently bound to GC. The surface layer was investigated electrochemically and identified using XPS. The structural conjugation of the resulting monolayer made it possible to initiate the electrochemical polymerization of EDOT from the modified surface. The polymeric structure formed on the thienyl-modified surface reveals a better redox peak separation as compared to the classical polymer film on a bare electrode that can be assigned to its more ordered and uniform structure.
Electron Technology, 2000
Applied Surface Science, 2017
Acta Physica Polonica A, 1984
Etude de la distribution des etats electroniques de surface dans la bande interdite de la surface... more Etude de la distribution des etats electroniques de surface dans la bande interdite de la surface (100) de GaAs type n recuit sous ultravide entre 500 et 800 K. Observation d'une bande d'etats de surface dans la bande interdite en dessous du niveau de Fermi. Correlations interessantes avec des etudes recentes de rendement photoelectrique
A control and characterisation of the surface/interface state density, NSS(E), is the key problem... more A control and characterisation of the surface/interface state density, NSS(E), is the key problem of III-V semiconductor technology. The powerful, contactless, and non-destructive technique for an assessment of NSS(E) for both free and covered surfaces is the photoluminescence surface state spectroscopy (PLS), which was developed by the group of Hasegawa [1]. In the PLS method, the band-edge photoluminescence (PL) efficiency YPL, i.e. the PL intensity divided by the excitation light intensity Φ, is measured as a function of Φ at room temperature. Then, the obtained YPL−Φ spectrum is compared with the theoretical curves rigorously calculated using a numerical simulator of photo-electronic phenomena in a semiconductor, in order to determine NSS(E) [1-3]. The simulator takes account of all possible processes of recombination in a bulk: band-to-band radiative transitions, Shockley-Read-Hall (SRH) recombination through deep levels, and Auger recombination, as well non-radiative recombina...
In this paper, the XPS study of SnO thin films deposited by the L-CVD technique are presented. The... more In this paper, the XPS study of SnO thin films deposited by the L-CVD technique are presented. The influence of exposition 2 of the as-deposited samples to oxygen O and hydrogen H on their stoichiometry was determined. Moreover, on the basis of 22 detailed shape analysis of the Sn3d and O1s XPS peaks, the chemical shift of binding energy corresponding to the change of 5 2 sample stoichiometry was separated from a shift of the binding energy corresponding to the change of interface Fermi levelposition E Fv E in the band gap, using a new procedure of deconvolution of the core level XPS peaks. The shift of the Sn3d5 2 peak by approximately 0.5 eV towards the lower binding energy after highest H exposure was interpreted as a true chemical 2 shift due to an increase of Sn 2 component, whereas the shift of Sn3d peak and O1s peak after highest O exposure by 5 22 approximately 0.5 eV towards the lower binding energy was interpreted as a result of the shift of the interface Fermi levelposition...
Applied Surface Science, 2018
Vacuum, 1999
In this paper a selfconstructed unipolar mass filter is presented together with a new method to d... more In this paper a selfconstructed unipolar mass filter is presented together with a new method to determine the partial pressures of gases with near atomic mass number desorbing from the surfaces during surface chemical reactions. It mainly uses the dependence of the efficiency of gas ionisation on the ionisation energy of electrons. Using the proposed procedure, the relative contents of methane and atomic oxygen observed during the cleaning of native oxide covered GaAs (1 0 0) surface by atomic hydrogen were estimated as 0.
Studies in Surface Science and Catalysis, 1985
Journal of Electron Spectroscopy and Related Phenomena, 1984
Photoemission yield spectroscopy (PYS) together with Auger electron spectroscopy (AES) have been ... more Photoemission yield spectroscopy (PYS) together with Auger electron spectroscopy (AES) have been used in an investigation of the electronic properties of the NiO(100) surface, thermally cleaned in ultrahigh vacuum (UHV). The work function and ionization energy were determined. The origin of the filled electronic states band localized below the Fermi level, EF, is briefly discussed.
ELEKTRONIKA - KONSTRUKCJE, TECHNOLOGIE, ZASTOSOWANIA, 2014
Applied Surface Science, 2012
This work presents the results of systematic X-ray photoelectron spectroscopy (XPS) and photoemis... more This work presents the results of systematic X-ray photoelectron spectroscopy (XPS) and photoemission yield spectroscopy (PYS) studies of the surface electronic properties of L-CVD SnO 2 ultrathin films submitted to various technological treatments. The interface Fermi level position in the band gap E F-E v has been determined from XPS analysis of the Sn3d 5/2 binding energy position. Such value of the Fermi level position was in a good agreement with the value estimated from the offset of XPS valence band. The variation of interface Fermi level position, after the various technological treatments, has been compared to the change of work function obtained by PYS. Valence band XPS spectra and PYS spectra point to the presence of two different bands of filled electronic states of the L-CVD SnO 2 thin films. The first one was localized in the upper part of valence band at the surface at about 6.0 eV below the Fermi level, whereas the second one was localized in the band gap at about 3.0 eV below the Fermi level. The changes of electronic properties of the space charge layer of L-CVD SnO 2 ultrathin films submitted to different technological procedures were assigned to the observed variation of their surface chemistry, including stoichiometry/nonstoichiometry and to the presence of surface carbon contamination.
Surface Science, 2009
The Kelvin method together with the simulations of surface photovoltage has been used to determin... more The Kelvin method together with the simulations of surface photovoltage has been used to determine the surface electronic properties, i.e. the surface band bending (qV S), surface state density (N SS0) and surface fixed charge (Q Fx) of S 2 Cl 2-treated GaAs (100) surfaces. The measured values of surface photovoltage (SPV) do not show saturation at high photon flux densities in contradiction to the simple theory of SPV. This behavior of SPV agrees very well with the rigorous computer simulations and can be explained in terms of the Dember effect. Moreover, the SPV values become insensitive to surface states at moderate photon flux densities. On this basis, the surface band bending of untreated (0.79 eV) and S 2 Cl 2-treated (0.60 eV) GaAs surfaces was determined. The band diagrams summarizing the obtained results proved the influence on the potential variations not only from the ionized surface states and surface fixed charge but also from the surface dipole layer on the S 2 Cl 2-treated GaAs surface. The dipole arises most probably due to the S-Ga bonding on the surface. The presented results offer an alternative explanation for increased PL commonly observed after the sulfidation in the absence of substantial reduction in the band bending.
High-resolution photoemission yield spectroscopy (PYS) has been used to study the electronic prop... more High-resolution photoemission yield spectroscopy (PYS) has been used to study the electronic properties of space charge layer of the real GaAs(100) surface cleaned by atomic hydrogen. The ionization energy, work function and interface Fermi level position were determined as a function of hydrogen dose. Moreover, the evolution of effective density of filled electronic states localized in the band gap and in the upper part of the valence band was observed. Our experiments showed that for the hydrogen dose up to 10 4 L H 2 the contamination etching stage occurs for which the interface Fermi level position E F-E v reaches a value of 1.06 eV. For the higher hydrogen dose at the level 10 5 L H 2 the interface Fermi level position E F-E v reaches a value of 0.75 eV which corresponds to the degradation of GaAs(100) surface that becomes covered by metallic Ga.