Influence of Molecular Order on the Local Work Function of Nanographene Architectures: A Kelvin‐Probe Force Microscopy Study

ChemPhysChem - Tập 6 Số 11 - Trang 2371-2375 - 2005
Vincenzo Palermo1, Matteo Palma1,2, Željko Tomović3, Mark D. Watson4,3, R. Friedlein5, Kläus Müllen3, Paolo Samorı́1,2
1Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, via Gobetti 101, 40129 Bologna, Italy
2Nanochemistry Laboratory, Institut de Science et d'Ingénierie, Supramoléculaires (ISIS), Université Louis Pasteur, 8, allée Gaspard Monge , 67083 Strasbourg, France
3Max-Planck Institute for Polymer Research, Ackermannweg 10, 55124 Mainz, Germany
4Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055 USA
5Department of Physics, IFM, Linköping University, 581 83 Linköping, Sweden

Tóm tắt

AbstractWe report a Kelvin‐probe force microscopy (KPFM) investigation on the structural and electronic properties of different submicron‐scale supramolecular architectures of a synthetic nanographene, including extended layers, percolated networks and broken patterns grown from solutions at surfaces. This study made it possible to determine the local work function (WF) of the differentπ‐conjugated nanostructures adsorbed on mica with a resolution below 10 nm and 0.05 eV. It revealed that the WF strongly depends on the local molecular order at the surface, in particular on the delocalization of electrons in theπ‐states, on the molecular orientation at surfaces, on the molecular packing density, on the presence of defects in the film and on the different conformations of the aliphatic peripheral chains that might cover the conjugated core. These results were confirmed by comparing the KPFM‐estimated local WF of layers supported on mica, where the molecules are preferentially packed edge‐on on the substrate, with the ultraviolet photoelectron spectroscopy microscopically measured WF of layers adsorbed on graphite, where the molecules should tend to assemble face‐on at the surface. It appears that local WF studies are of paramount importance for understanding the electronic properties of active organic nanostructures, being therefore fundamental for the building of high‐performance organic electronic devices, including field‐effect transistors, light‐emitting diodes and solar cells.

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Tài liệu tham khảo

10.1038/16393

10.1038/nature02498

10.1038/nmat1182

Kittel C., 2005, Introduction to Solid State Physics

10.1063/1.1583533

Salaneck W. R., 2003, Conjugated Polymer Surfaces and Interfaces: Electronic and Chemical Structure of Interfaces for Polymer Light Emitting Devices

10.1002/(SICI)1521-4095(199906)11:8<605::AID-ADMA605>3.0.CO;2-Q

10.1063/1.105227

10.1103/PhysRevLett.63.2669

10.1021/ja028524h

10.1063/1.1592888

10.1002/(SICI)1096-9918(199905/06)27:5/6<361::AID-SIA482>3.0.CO;2-8

10.1016/S0304-3991(97)00027-2

10.1063/1.124357

10.1088/0957-4484/15/2/007

10.1021/la034187u

10.1002/1521-4095(200105)13:9<631::AID-ADMA631>3.0.CO;2-F

10.1002/1521-3765(20011119)7:22<4894::AID-CHEM4894>3.0.CO;2-S

10.1143/JJAP.42.4852

10.1063/1.1470702

10.1063/1.1637443

10.1021/cr990322p

10.1103/PhysRevLett.92.188303

10.1021/ja0111380

10.1021/ja020323q

10.1103/PhysRevB.68.195414

10.1002/adma.200390114

10.1021/ja037519q

10.1021/ja038648

10.1021/ja0395994

10.1126/science.293.5532.1119

10.1002/anie.200352855

10.1002/(SICI)1521-3765(19990802)5:8<2312::AID-CHEM2312>3.0.CO;2-F

10.1006/jcis.1996.0133

10.1038/nature02087

V. Palermo M. Palma Z. Tomovic K. Müllen P. Samorì unpublished results.

Okamoto K., 2003, Jpn. J. Appl. Phys. Part 1‐Regular Papers Short Notes & Review Papers, 7163

Wolf H. W., 1971, Semiconductors

Pruton M., 1994, Introduction to Surface Physics, 10.1093/oso/9780198534754.001.0001

10.1063/1.368181

Fadley C. S., 1978, Electron Spectroscopy: Theory, Techniques, and Applications

10.1021/jp004076t

S. Goddard unpublished results.

10.1016/S0009-2614(02)00148-3

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ChemPhysChem

Tập 6 Số 11

2371-2375

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