Article (Scientific journals)
Tuning the work function of stepped metal surfaces by adsorption of organic molecules
Jiang, Yingda; Li, Jingtai; Su, Guirong et al.
2017In Journal of Physics: Condensed Matter, 29, p. 204001
Peer Reviewed verified by ORBi
 

Files


Full Text
100-stepped-surfaces-workfunctions-JPCM-2017.pdf
Publisher postprint (1.3 MB)
Download

All documents in ORBilu are protected by a user license.

Send to



Details



Abstract :
[en] Understanding the binding mechanisms for aromatic molecules on transition-metal surfaces, especially with defects such as vacancies, steps and kinks, is a major challenge in designing functional interfaces for organic devices. One important parameter in the performance of organic/inorganic devices is the barrier of charge carrier injection. In the case of a metallic electrode, tuning the electronic interface potential or the work function for electronic level alignment is crucial. Here, we use density-functional theory (DFT) calculations with van der Waals (vdW) interactions treated with both screened pairwise (vdWsurf) and many-body dispersion (MBD) methods, to systematically study the interactions of benzene with a variety of stepped surfaces. Our calculations confirm the physisorptive character of Ag(2 1 1), Ag(5 3 3), Ag(3 2 2), Ag(7 5 5) and Ag(5 4 4) surfaces upon the adsorption of benzene. The MBD effects reduce the adsorption energies by about 0.15 eV per molecule compared to the results from the DFT + vdWsurf method. In addition, we find that the higher the step density, the larger the reduction of the work function upon the adsorption of benzene. We also study the effect of vdW interactions on the electronic structure using a fully selfconsistent implementation of the vdWsurf method in the Kohn–Sham DFT framework. We find that the self-consistent vdWsurf effects increase the work function due to the lowered Fermi level and the increased vacuum level. As a result, the benzene/Ag(2 1 1) system has the lowest work function (3.67 eV) among the five adsorption systems, significantly smaller than the work function of the clean Ag(1 1 1) surface (4.74 eV). Our results provide important insights into the stability and electronic properties of molecules adsorbed on stepped metal surfaces, which could help in designing more appropriate interfaces with low work functions for electron transfer.
Disciplines :
Physics
Author, co-author :
Jiang, Yingda
Li, Jingtai
Su, Guirong
Ferri, Nicola
Liu, Wei
Tkatchenko, Alexandre ;  University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
External co-authors :
yes
Language :
English
Title :
Tuning the work function of stepped metal surfaces by adsorption of organic molecules
Publication date :
2017
Journal title :
Journal of Physics: Condensed Matter
ISSN :
1361-648X
Publisher :
Institute of Physics, Bristol, United Kingdom
Volume :
29
Pages :
204001
Peer reviewed :
Peer Reviewed verified by ORBi
Focus Area :
Computational Sciences
Physics and Materials Science
Available on ORBilu :
since 13 May 2017

Statistics


Number of views
157 (2 by Unilu)
Number of downloads
484 (1 by Unilu)

Scopus citations®
 
19
Scopus citations®
without self-citations
16
WoS citations
 
18

Bibliography


Similar publications



Contact ORBilu