Two-Dimensional Crystals as a Buffer Layer for High Work Function Applications: The Case of Monolayer MoO 3 .

Autor: Kowalczyk DA; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Rogala M; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Szałowski K; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Belić D; Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, 22100 Lund, Sweden.; Department of Physics, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia., Dąbrowski P; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Krukowski P; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Lutsyk I; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Piskorski M; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Nadolska A; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Krempiński P; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Le Ster M; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland., Kowalczyk PJ; Department of Solid State Physics (Member of National Photovoltaic Laboratory, Poland), Faculty of Physics and Applied Informatics, University of Lodz, Pomorska 149/153, 90-236 Łódź, Poland.
Jazyk: angličtina
Zdroj: ACS applied materials & interfaces [ACS Appl Mater Interfaces] 2022 Oct 05; Vol. 14 (39), pp. 44506-44515. Date of Electronic Publication: 2022 Aug 17.
DOI: 10.1021/acsami.2c09946
Abstrakt: We propose that the crystallinity of two-dimensional (2D) materials is a crucial factor for achieving highly effective work function (WF) modification. A crystalline 2D MoO 3 monolayer enhances substrate WF up to 6.4 eV for thicknesses as low as 0.7 nm. Such a high WF makes 2D MoO 3 a great candidate for tuning properties of anode materials and for the future design of organic electronic devices, where accurate evaluation of the WF is crucial. We provide a detailed investigation of WF of 2D α-MoO 3 directly grown on highly ordered pyrolytic graphite, by means of Kelvin probe force microscopy (KPFM) and ultraviolet photoemission spectroscopy (UPS). This study underlines the importance of a controlled environment and the resulting crystallinity to achieve high WF in MoO 3 . UPS is proved to be suitable for determining higher WF attributed to 2D islands on a substrate with lower WF, yet only in particular cases of sufficient coverage. KPFM remains a method of choice for nanoscale investigations, especially when conducted under ultrahigh vacuum conditions. Our experimental results are supported by density functional theory calculations of electrostatic potential, which indicate that oxygen vacancies result in anisotropy of WF at the sides of the MoO 3 monolayer. These novel insights into the electronic properties of 2D-MoO 3 are promising for the design of electronic devices with high WF monolayer films, preserving the transparency and flexibility of the systems.
Databáze: MEDLINE
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