Impact of Nanomorphology on Surface Doping of Organic Semiconductors: The Pentacene−C60F48 Interface

Autor: Esther Barrena, Francesco Silvestri, Liviu Cristian Tanase, Adara Babuji, Lucas de Souza Caldas, Thomas Schmidt, Olga Solomeshch, Carmen Ocal, Mauricio J. Prieto
Přispěvatelé: Ministerio de Economía y Competitividad (España), European Commission, Generalitat de Catalunya, Federal Ministry of Education and Research (Germany), Max Planck Society, German Research Foundation, Ministry of Science, Technology and Space (Israel)
Rok vydání: 2020
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
instname
ACS Applied Materials & Interfaces
Popis: Establishing the rather complex correlation between the structure and the charge transfer in organic−organic heterostructures is of utmost importance for organic electronics and requires spatially resolved structural, chemical, and electronic details. Insight into this issue is provided here by combining atomic force microscopy, Kelvin probe force microscopy, photoemission electron microscopy, and low-energy electron microscopy for investigating a case study. We select the interface formed by pentacene (PEN), benchmark among the donor organic semiconductors, and a p-type dopant from the family of fluorinated fullerenes. As for Buckminsterfullerene (C60), the growth of its fluorinated derivative C60F48 is influenced by the thickness and crystallinity of the PEN buffer layer, but the behavior is markedly different. We provide a microscopic description of the C60F48/PEN interface formation and analyze the consequences in the electronic properties of the final heterostructure. For just one single layer of PEN, a laterally complete but noncompact C60F48/PEN interface is created, importantly affecting the surface work function. Nonetheless, from the very beginning of the second layer formation, the presence of epitaxial and nonepitaxial PEN domains dramatically influences the growth dynamics and extremely well packed two-dimensional C60F48 islands develop. Insightful elemental maps of the C60F48/PEN surface spatially resolve the nonuniform distribution of the dopant molecules, which leads to a heterogeneous work function landscape.
This work has been supported by the Spanish government under the projects MAT2016-77852-C2-1-R (AEI/FEDER, UE) and the “Severo Ochoa” Program for Centers of Excellence in R&D (SEV-2015-0496) and by the European Union’s Horizon 2020 Research and Innovation Program under grant Agreement No. 730872 and the Marie Skłodowska-Curie Grant Agreement No. 722651 (SEPOMO project). We also acknowledge the Generalitat de Catalunya grant 2017 SGR668. F.S. has been developing this work as part of his doctorate in Materials Science at the Universitat Autonoma de Barcelona (UAB). The SMART instrument was ̀ financially supported by the Federal German Ministry of Education and Research (BMBF) under the contract 05 KS4WWB/4, as well as by the Max-Planck Society. We thank the Helmholtz-Center Berlin for Materials and Energy (HZB) for the allocation of beamtime 192-08486-ST. L.d.S.C. is grateful for the funding through the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany′s Excellence StrategyEXC 2008390540038 (UniSysCat). O.S. acknowledges the support from the Israel Ministry of Science, the Center for Absorption in Science of the Ministry of Immigrant Absorption, the Committee for Planning and budgeting of the Council for Higher Education under the framework of the KAMEA Program.
Databáze: OpenAIRE
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