uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Electronic Structure Study of Free and Adsorbed m-MTDATA
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.ORCID iD: 0000-0001-8739-7773
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics.ORCID iD: 0000-0003-1671-8298
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
ISM-CNR, Trieste LD2 Unit, Italy.
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The starburst p-conjugated molecule based on triphenylamine (TPA) building block, 4,4',4" -Tris(N-3-methylphenyl-N-phenyl-amino)triphenylamine (m-MTDATA), is widely used in optoelectronic devices due to its electron-donating properties. The electronic structure of m-MTDATA was investigated in the gas-phase and when deposited in thin films on a Au(111) surface by means of PhotoElectron Spectroscopy (PES) and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. Density Functional Theory (DFT) calculations were compared to the experimental gas-phase results, providing a comprehensive description of the molecular electronic structure. Moreover, the results were compared with previous TPA measurements, shedding light on the electronic structure modification due to the increased molecular complexity.  Similar to TPA, but more complex, the binding energy of the C 1s photoelectron line of m-MTDATA results from the balance of two counter-acting effects: (1) the electronegativity of the N atoms and (2) the delocalization of lone-pair electrons of the nitrogen. Compared to TPA, the outermost valence PE spectrum of m-MTDATA shows a 3-peak feature with N 2pz character and a lowering of the binding energy of the HOMO. When adsorbed on Au(111),  the changes observed in PES and NEXAFS spectra with respect to the free molecules,  can be explained by a significant modification of m-MTDATA molecular and electronic structure, due to the molecule-substrate interaction.

National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:uu:diva-355121OAI: oai:DiVA.org:uu-355121DiVA, id: diva2:1228914
Available from: 2018-06-29 Created: 2018-06-29 Last updated: 2018-06-29
In thesis
1. Synchrotron Radiation Studies of Molecular Building Blocks for Functional Materials
Open this publication in new window or tab >>Synchrotron Radiation Studies of Molecular Building Blocks for Functional Materials
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The research on new materials is a primary driving force for progress in human society. One of the most significant research topic nowadays is the development of new functional materials for technological applications, like perovskite implemented in solar cells, and graphene as a representative for the new 2D materials family. It is then crucial to fully understand the functionality of such materials from a fundamental point of view, as a complementary and useful guide to develop/design new devices of improved performance and energy efficiency.

In the thesis, comprehensive characterizations of molecular building blocks used in i) novel energy conversion devices (CoPc, TPA, DPTA and m-MTDATA), and ii) in 2D materials (biphenylene and melamine) have been performed by PhotoElectron Spectroscopy (PES), and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy carried out at synchrotron radiation facilities, representing effective, powerful light source dedicated to the front-line materials research of great value in both science and industry. PES and NEXAFS spectroscopy, in combination with Density Functional Theory (DFT) calculations have provided a deep understanding of the electronic structure of the investigated systems in relation to their functionality. The investigations always included the combination and comparison between experimental and theoretical results. The studied molecules were characterized as free and adsorbed on surfaces, from the simple building blocks to more complex molecular systems. The characterizations allowed us to identify the electronic structure modifications due to substitutions (Paper III), increasing complexity of the molecules (Paper V), molecule-substrate interactions (Paper I, II, IV, V) and intra-molecular H-bonding interactions (Paper VI).

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2018. p. 97
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1693
Keywords
Synchrotron radiation study, Functional materials, Molecular building blocks, Electron donor, 2D material, Gas-phase, Organic thin film, Electronic structure, Molecule-molecule interaction, Molecule-substrate interaction, Photoelectron spectroscopy, PES, XPS, Near edge X-ray absorption fine structure, NEXAFS, X-ray Absorption Spectroscopy, XAS, Au(111), Cu(111), Surface, Interface, Electronic structure, H-bonding, Cobalt phthalocyanine, CoPc, Triphenylamine, TPA, DPTA, m-MTDATA, Melamine, Biphenylene, Carbon nitride, Graphenylene, Density functional theory, DFT
National Category
Atom and Molecular Physics and Optics Condensed Matter Physics
Research subject
Physics with spec. in Atomic, Molecular and Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-354766 (URN)978-91-513-0383-3 (ISBN)
Public defence
2018-09-07, Häggsalen, Ångström Laboratory, Lägerhyddsvägen 1, Uppsala, 10:15 (English)
Opponent
Supervisors
Available from: 2018-08-14 Created: 2018-06-29 Last updated: 2018-08-28

Open Access in DiVA

No full text in DiVA

Authority records BETA

Zhang, TengBrumboiu, Iulia E.Lanzilotto, ValeriaJohansson, FredrikBrena, BarbaraPuglia, Carla

Search in DiVA

By author/editor
Zhang, TengBrumboiu, Iulia E.Lanzilotto, ValeriaJohansson, FredrikBrena, BarbaraPuglia, Carla
By organisation
Molecular and Condensed Matter PhysicsMaterials TheoryTheoretical Physics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 43 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf