Hohmann, Mareike V. ; Ágoston, Péter ; Wachau, André ; Bayer, Thorsten J. M. ; Broetz, Joachim ; Albe, Karsten ; Klein, Andreas (2011)
Orientation dependent ionization potential of In2O3: A natural source for inhomogeneous barrier formation at electrode interfaces in organic electronics.
In: Journal of Physics: Condensed Matter, 23 (33)
doi: 10.1088/0953-8984/23/33/334203
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The ionization potentials of In2O3 films grown epitaxially by magnetron sputtering on Y-stabilized ZrO2 substrates with (100) and (111) surface orientation are determined using photoelectron spectroscopy. Epitaxial growth is verified using x-ray diffraction. The observed ionization potentials, which directly affect the work functions, are in good agreement with ab initio calculations using density functional theory. While the (111) surface exhibits a stable surface termination with an ionization potential of ~ 7.0 eV, the surface termination and the ionization potential of the (100) surface depend strongly on the oxygen chemical potential. With the given deposition conditions an ionization potential of ~ 7.7 eV is obtained, which is attributed to a surface termination stabilized by oxygen dimers. This orientation dependence also explains the lower ionization potentials observed for In2O3 compared to Sn-doped In2O3 (ITO) (Klein et al 2009 Thin Solid Films 518 1197–203). Due to the orientation dependent ionization potential, a polycrystalline ITO film will exhibit a laterally varying work function, which results in an inhomogeneous charge injection into organic semiconductors when used as electrode material. The variation of work function will become even more pronounced when oxygen plasma or UV–ozone treatments are performed, as an oxidation of the surface is only possible for the (100) surface. The influence of the deposition technique on the formation of stable surface terminations is also discussed.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2011 |
| Autor(en): | Hohmann, Mareike V. ; Ágoston, Péter ; Wachau, André ; Bayer, Thorsten J. M. ; Broetz, Joachim ; Albe, Karsten ; Klein, Andreas |
| Art des Eintrags: | Bibliographie |
| Titel: | Orientation dependent ionization potential of In2O3: A natural source for inhomogeneous barrier formation at electrode interfaces in organic electronics |
| Sprache: | Englisch |
| Publikationsjahr: | 2 August 2011 |
| Verlag: | IOP Publishing |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Physics: Condensed Matter |
| Jahrgang/Volume einer Zeitschrift: | 23 |
| (Heft-)Nummer: | 33 |
| DOI: | 10.1088/0953-8984/23/33/334203 |
| Kurzbeschreibung (Abstract): | The ionization potentials of In2O3 films grown epitaxially by magnetron sputtering on Y-stabilized ZrO2 substrates with (100) and (111) surface orientation are determined using photoelectron spectroscopy. Epitaxial growth is verified using x-ray diffraction. The observed ionization potentials, which directly affect the work functions, are in good agreement with ab initio calculations using density functional theory. While the (111) surface exhibits a stable surface termination with an ionization potential of ~ 7.0 eV, the surface termination and the ionization potential of the (100) surface depend strongly on the oxygen chemical potential. With the given deposition conditions an ionization potential of ~ 7.7 eV is obtained, which is attributed to a surface termination stabilized by oxygen dimers. This orientation dependence also explains the lower ionization potentials observed for In2O3 compared to Sn-doped In2O3 (ITO) (Klein et al 2009 Thin Solid Films 518 1197–203). Due to the orientation dependent ionization potential, a polycrystalline ITO film will exhibit a laterally varying work function, which results in an inhomogeneous charge injection into organic semiconductors when used as electrode material. The variation of work function will become even more pronounced when oxygen plasma or UV–ozone treatments are performed, as an oxidation of the surface is only possible for the (100) surface. The influence of the deposition technique on the formation of stable surface terminations is also discussed. |
| Freie Schlagworte: | electrical, magnetic and optical Surfaces; interfaces and thin films |
| Zusätzliche Informationen: | SFB 595 D3 |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Materialmodellierung 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Oberflächenforschung 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Strukturforschung DFG-Sonderforschungsbereiche (inkl. Transregio) DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche Zentrale Einrichtungen DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > D - Bauteileigenschaften DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > D - Bauteileigenschaften > Teilprojekt D3: Funktion und Ermüdung oxidischer Elektroden in organischen Leuchtdioden |
| Hinterlegungsdatum: | 17 Sep 2012 12:59 |
| Letzte Änderung: | 27 Jan 2021 10:41 |
| PPN: | |
| Sponsoren: | This work was supported by the Deutsche Forschungsgemeinschaft (DFG) within the collaborative research center SFB 595 (Electrical Fatigue of Functional Materials). |
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