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
Structure and Electronic Properties of Phthalocyanine Films on Metal and Semiconductor Substrates
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The current thesis presents fundamental studies of phthalocyanines (Pcs), a group of organic macro-cycle molecules. The use of phthalocyanine molecular films in devices with a variety of possible technological applications has been the reason of the many studies dedicated to such molecules during the last decades.

Core and valence photoelectron spectroscopies (PES), X-ray absorption spectroscopy (XAS) and scanning tunneling microscopy (STM) techniques are used to study phthalocyanine molecules in gas phase and adsorbed on gold (111) and silicon Si(100)-2x1 substrates. Density functional theory (DFT) is used to obtain further insights in the electronic structure of the phthalocyanines.

The aim of our studies is to get a deeper understanding into the molecule-molecule and molecule-substrate interactions, a fundamental requirement for improving the devices based on such molecular materials.

Gas phase PES and XAS studies and single molecule DFT calculations are performed on the valence band (VB) of iron phthalocyanine (FePc), manganese phthalocyanine (MnPc) and metal-free phthalocyanine (H2Pc). The VB simulations have shown how the metal atom of the Pc influences the inner valence states of the molecules. The HOMO of the H2Pc and FePc is formed by mostly C2p states, whereas the HOMO of MnPc has mainly Mn3d character.

PES studies of H2Pc on Au(111) have revealed the influence of the surface on the adsorption of the monolayer. XAS studies indicate formation of ordered monolayer with the Pc ligands parallel to the surface and the change of the molecular tilt angle with increasing thicknesses. For LuPc2 adsorbed on Au(111), STM study demonstrates a formation of bilayer instead of a monolayer.

A comparison between the results of LuPc2 adsorbed on pristine or passivated Si(100)-2x1 confirmes the different reactivities of these surfaces: LuPc2 retains many molecular-like characters, when adsorbed on the innert passivated Si. Instead, on the more reactive pristine Si surface, the spectroscopic results have indicated a more significant interaction, possible hybridization and charge redistribution between the molecules and the surface. Moreover, STM images show a modification of the geometrical shape of the molecules, which are proposed to adsorb in two different geometries on the pristine Si surface.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2014. , 51 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1119
Keyword [en]
Phthalocyanines, silicon(100), Au(111), photoelectron spectroscopy, scanning tunneling microscopy, surface science, organic molecules on surface
National Category
Natural Sciences Condensed Matter Physics
Identifiers
URN: urn:nbn:se:uu:diva-217086ISBN: 978-91-554-8867-3 (print)OAI: oai:DiVA.org:uu-217086DiVA: diva2:692075
Public defence
2014-03-14, Häggsalen, Ångström Laboratory, Lägerhyddsvägen 1, Uppsala, 10:15 (English)
Opponent
Supervisors
Available from: 2014-02-21 Created: 2014-01-29 Last updated: 2014-04-29
List of papers
1. Experimental and theoretical study of electronic structure of lutetium bi-phthalocyanine
Open this publication in new window or tab >>Experimental and theoretical study of electronic structure of lutetium bi-phthalocyanine
Show others...
2013 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 138, no 23, 234701- p.Article in journal (Refereed) Published
Abstract [en]

Using Near Edge X-Ray Absorption Fine Structure (NEXAFS) Spectroscopy, the thickness dependent formation of Lutetium Phthalocyanine (LuPc2) films on a stepped passivated Si(100)2x1 reconstructed surface was studied. Density functional theory (DFT) calculations were employed to gain detailed insights into the electronic structure. Photoelectron spectroscopy measurements have not revealed any noticeable interaction of LuPc2 with the H-passivated Si surface. The presented study can be considered to give a comprehensive description of the LuPc2 molecular electronic structure. The DFT calculations reveal the interaction of the two molecular rings with each other and with the metallic center forming new kinds of orbitals in between the phthalocyanine rings, which allows to better understand the experimentally obtained NEXAFS results. 

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-205011 (URN)10.1063/1.4809725 (DOI)000321012400026 ()
Available from: 2013-08-13 Created: 2013-08-13 Last updated: 2017-12-06Bibliographically approved
2. Adsorption and Molecular Orientation of Lutetium bi-Phthalocyanine Adlayers on Pristine Si(100)2x1 Surface
Open this publication in new window or tab >>Adsorption and Molecular Orientation of Lutetium bi-Phthalocyanine Adlayers on Pristine Si(100)2x1 Surface
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

A combined photoelectron spectroscopy (PES), X-ray absorption spectroscopy (XAS)

and scanning tunneling microscopy (STM) study has been performed to follow the

change in adsorption geometry and to characterize the adsorbate interaction with the

substrate for dierent thicknesses of lutetium biphthalocyanine (LuPc2) adlayers on

pristine Si(100)-2x1 reconstructed stepped surface. A shift to lower binding energies

with increasing thickness has been shown. The STM results showed clustering of

LuPc2 starting from submonolayer coverages and two distinct adsorption types have

been identied. The STM and PES results have been linked together to propose two

dierent adsorption types involving a stronger and weaker interaction with the Si

dangling bonds. A change in average angle of molecules with respect to the normal

of the surface for increasing thicknesses has been seen from the XAS measurements,

leading to disordered layers for thicker films.

Keyword
silicon, phthalocyanines, photoelectron spectroscopy, scanning tunneling microscopy
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-217079 (URN)
Available from: 2014-01-29 Created: 2014-01-29 Last updated: 2014-04-29
3. Photoelectron and Absorption Spectroscopy Studies of Metal-Free Phthalocyanine on Au(111): Experiment and Theory
Open this publication in new window or tab >>Photoelectron and Absorption Spectroscopy Studies of Metal-Free Phthalocyanine on Au(111): Experiment and Theory
Show others...
2013 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 117, no 14, 7018-7025 p.Article in journal (Refereed) Published
Abstract [en]

The adsorption of monolayers and multilayers of metal-free phthalocyanine molecules on the Au(111) (root 3 x 22) reconstructed surface has been investigated by X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). Our results for the monolayer show that the molecules are arranged tightly onto the surface with their molecular plane parallel to it. In addition, the X-ray absorption spectra of the monolayer have been modeled by density functional theory, which could enlighten new aspect of the interaction between molecules and substrate. The XAS results evidence that also in the multilayer the molecules keep the orientation with the molecular plane parallel to the surface. These results are discussed in the framework of moleculemolecule/moleculeadsorbate interactions.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-200064 (URN)10.1021/jp307626n (DOI)000317552200015 ()
Available from: 2013-05-23 Created: 2013-05-20 Last updated: 2017-12-06Bibliographically approved
4. Formation of Self-organized bi-Layer of LuPc2 Molecules on Gold (111) Surface
Open this publication in new window or tab >>Formation of Self-organized bi-Layer of LuPc2 Molecules on Gold (111) Surface
Show others...
(English)Manuscript (preprint) (Other academic)
Keyword
Au(111), phthalocyanines, STM, bi-layer, XPS
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-217081 (URN)
Available from: 2014-01-29 Created: 2014-01-29 Last updated: 2014-04-29
5. Characterization of Gas Phase of Iron Phthalocyanine with X-ray Photoelectron and Absorption Spectroscopies
Open this publication in new window or tab >>Characterization of Gas Phase of Iron Phthalocyanine with X-ray Photoelectron and Absorption Spectroscopies
Show others...
2015 (English)In: Physica status solidi. B, Basic research, ISSN 0370-1972, E-ISSN 1521-3951, Vol. 252, no 6, 1259-1265 p.Article in journal (Refereed) Published
Abstract [en]

Despite the numerous studies dedicated to phthalocyanine molecules adsorbed on surfaces, in monolayer or thin film, very few works have been focused on the characterization of vapors of these molecules. In this article we present the C 1s, N 1s and Fe 2p photoemission results as well as N K-edge X-ray absorption data of iron phthalocyanine (FePc) in gas phase. Presented comparison of X-ray photoelectron spectroscopy and X-ray absorption spectroscopy spectra of FePc films show a great similarity with the gas phase results, confirming the molecular character of thick films. The Fe2p photoemission spectrum of the gas phase FePc, shown for the first time, can be considered as a fingerprint of the Fe(II) ionic state of the central metal of the iron phthalocyanine. The performed multiplet calculations for describing the Fe 2p XP spectrum indicate 3Eg (a1g2eg32g1) state as the most probable ground state for thick film of iron phthalocyanine.

National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:uu:diva-217080 (URN)10.1002/pssb.201451147 (DOI)000355756200010 ()
Funder
Swedish Research CouncilCarl Tryggers foundation
Available from: 2014-01-29 Created: 2014-01-29 Last updated: 2017-12-06Bibliographically approved
6. Atomic Contributions to the Valence Band Photoelectron Spectra of Metal-free, Iron and Manganese Phthalocyanines
Open this publication in new window or tab >>Atomic Contributions to the Valence Band Photoelectron Spectra of Metal-free, Iron and Manganese Phthalocyanines
Show others...
2015 (English)In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 205, 92-97 p.Article, review/survey (Other academic) Published
Abstract [en]

The present work reports a photoelectron spectroscopy study of the low-energy region of the valence band of metal-free phthalocyanine (H2Pc) compared with those of iron phthalocyanine (FePc) and manganese phthalocyanine (MnPc). We have analysed in detail the atomic orbital composition of the valence band both experimentally, by making use of the variation in photoionization cross-sections with photon energy, and theoretically, by means of density functional theory. The atomic character of the Highest Occupied Molecular Orbital (HOMO), reflected on the outermost valence band binding energy region, is different for MnPc as compared to the other two molecules. The peaks related to the C 2p contributions, result in the HOMO for H2Pc and FePc and in the HOMO-1 for MnPc as described by the theoretical predictions, in very good agreement with the experimental results. The DFT simulations, discerning the atomic contribution to the density of states, indicate how the central metal atom interacts with the C and N atoms of the molecule, giving rise to different partial and total density of states for these three Pc molecules.

Keyword
Valence band; X-ray photoelectron spectroscopy; DFT; Phthalocyanines
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:uu:diva-217083 (URN)10.1016/j.elspec.2015.09.004 (DOI)000367282400011 ()
Funder
Swedish Research CouncilKnut and Alice Wallenberg FoundationCarl Tryggers foundation
Available from: 2014-01-29 Created: 2014-01-29 Last updated: 2017-12-06Bibliographically approved

Open Access in DiVA

fulltext(15698 kB)791 downloads
File information
File name FULLTEXT01.pdfFile size 15698 kBChecksum SHA-512
5be21322b179b0e866ec4e66a2f221d30e2e9b3705ac477e9f621adf910fcb31ef55a995206ee79f60d03691e1fca7d5d71431c96f45822ca1ced6dbf743a5c5
Type fulltextMimetype application/pdf
Buy this publication >>

Authority records BETA

Bidermane, Ieva

Search in DiVA

By author/editor
Bidermane, Ieva
By organisation
Molecular and condensed matter physics
Natural SciencesCondensed Matter Physics

Search outside of DiVA

GoogleGoogle Scholar
Total: 791 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1109 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