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

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 comb...

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Detalles Bibliográficos
Autores: Silvestri, Francesco, Prieto, Mauricio J., Babuji, Adara, Tănase, Liviu C., Caldas, Lucas de Souza, Solomeshch, Olga, Schmidt, Thomas, Ocal, Carmen, Barrena, Esther
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2020
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/214214
Acceso en línea:http://hdl.handle.net/10261/214214
Access Level:acceso abierto
Palabra clave:organic semiconductors
molecular doping
Interface
nanomorphology
pentacene
C60F48
AFM
XPEEM
Descripción
Sumario: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.