Max Bommert¹, Bruno Schuler¹, Carlo A. Pignedoli^1*, Roland Widmer¹, Oliver Gröning^1*

1 Empa – Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland

* Corresponding authors emails: carlo.pignedoli@empa.ch, oliver.groening@empa.ch

DOI10.24435/materialscloud:a5-sh [version v1]

Publication date: Jan 09, 2024

How to cite this record

Max Bommert, Bruno Schuler, Carlo A. Pignedoli, Roland Widmer, Oliver Gröning, Ambipolar charge transfer of larger fullerenes enabled by the modulated surface potential of h-BN/Rh(111), Materials Cloud Archive 2024.7 (2024), https://doi.org/10.24435/materialscloud:a5-sh

Description

A detailed understanding of how molecules interact with two-dimensional materials, particularly concerning energy level alignment and charge transfer processes, is essential to incorporate functional molecular films into next-generation 2D material-organic hybrid devices. One of the major challenges in integrating molecular films in field-effect transistors is facilitating ambipolar charge transport, which is often hindered by the large electronic gap of the organic layers. In a recent work we compare the adsorption site-dependent energy level alignment of C60, C70, and C84 fullerenes induced by the spatial variation of the electrostatic surface potential of the h-BN/Rh(111) Moiré superstructure. As the size of the fullerenes increases, the HOMO-LUMO gap shrinks. In the case of C84, we find an intrinsic charge transfer from the substrate to the fullerenes adsorbed in the Moiré pore centers, rendering them negatively charged. The electric field effect-induced charging of neutral fullerenes and discharging of intrinsically negatively charged fullerenes are investigated using scanning tunneling spectroscopy, non-contact atomic force microscopy, and Kelvin probe force spectroscopy. Our findings show that on metal-supported h-BN, the LUMO level of C84 is sufficiently close to the Fermi energy that it can be neutral or 1e− negatively charged depending on slight variations of the electrostatic potential. The findings propose a path to make ambipolar charge transfer accessible and efficient by circumventing the need to overcome the fullerenes’ electronic gap. This record contain data that support the results discussed in our work.

Materials Cloud sections using this data

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File name	Size	Description
ReadMe.yaml MD5md5:3e0613d2a130e2c15f7781498589c131	15.8 KiB	ReadMe file in yaml format containing the list of files of the record
C84-gaussian.aiida MD5md5:f9a014166aa70a6a393d800365764422 Open this AiiDA archive on renkulab.io (https://renkulab.io/)	135.1 MiB	Archive file containing aiida nodes of the calculations
data.tgz MD5md5:e26903a49d9117974a87f1a0ba80e90b	14.9 MiB	Tar file containing all files of the record

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External references

Keywords

Fullerenes MARVEL/P4 ab initio CSCS SNSF 2D materials Ambipolar charge transfer Intermolecular interactions Organic hybrid electronics Scanning tunneling microscopy Non-contact atomic force microscopy