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Low-energy electron transmission for the analysis of the interface barrier formation and the density of the unoccupied electronic states in the ultra-thin layers of fluorinated copper-phthalocyanine

A. S. Komolov
    / E. F. Lazneva
      / S. N. Akhremtchik
        / N. B. Gerasimova
          / S. A. Pshenichnyuk
            Published Online: 2015-01-29 | DOI: https://doi.org/10.1515/oph-2015-0002


            The interfacial structure made from the thermally deposited 5 – 7 nm thick layers of hexadecafluoro copper phthalocyanine (F16-CuPc) and of the unsubstituted copper phthalocyanine (CuPc) was subjected to the studies. The surface work function and the density of the unoccupied electron states (DOUS) located 5- 20 eV above the Fermi level (EF) were investigated during the CuPc/F16-CuPc interface formation using the very low energy electron diffraction (VLEED) method and the total current spectroscopy (TCS) measurement scheme. The DOUS peak structure of the organic films studied obtained from the TCS results showed a good correspondence to the main π* and σ* DOUS bands obtained from the density functional theory (DFT) calculations. The interfacial barrier was characterized by the negative charge transfer from the CuPc overlayer to the F16-CuPc underlayer occurred within the 5 nm thick interfacial region in the CuPc overlayer which was accompanied by the decrease of the surface work function from 4.9±0.1 eV to 4.3±0.1 eV. The stabilization of the π* DOUS bands, as well as restructuring of the low lying σ* bands was observed in the in the case of the fluorinated film (F16- CuPc) compared to the case of the unsubstituted CuPc film.

            Keywords: Organic semiconducting films; Surface electronic phenomena (work function, surface potential, surface states, etc.); interface charge transfer; DFT calculations; Density of states


            • [1] J. Jo, J.-R. Pouliot, D.Wynands, S.D. Collins, J.Y. Kim, T.L. Nguyen, H.Y. Woo, Y. Sun, M. Leclerc and A.J. Heeger, Enhanced Eflciency of Single and Tandem Organic Solar Cells Incorporating a Diketopyrrolopyrrole-Based Low-Bandgap Polymer by Utilizing Combined ZnO/Polyelectrolyte Electron-Transport Layers, Adv. Mater. 25(34), 2013, 4783. [Web of Science]

            • [2] A.N. Aleshin, I.P. Sherbakov, V.N. Petrov and A.N. Titkov, Solution-processed polyfluorene–ZnOnanoparticlesambipolar light-emitting field-effect transistor, Organic Electr. 12, 2011, 1285.

            • [3] S. M. Yoon, S. J. Lou, S. Loser, J. Smith, L. X. Chen, A. Facchetti and T. J. Marks, Fluorinated Copper Phthalocyanine Nanowires for Enhancing Interfacial Electron Transport in Organic Solar Cells, Nano Lett. 12(12), 2012, 6315. [Crossref] [Web of Science]

            • [4] A. Y. Sosorev, O. D. Parashchuk, S. A. Zapunidi, G. S. Kashtanov and D. Y. Paraschuk, Intrachain Aggregation of Charge- Transfer Complexes in Conjugated Polymer: Acceptor Blends from Photoluminescence Quenching, J. Phys. Chem. C, 117(14), 2013, 6972. [Web of Science]

            • [5] J. Min, H. Zhang, T. Stubhan, Y.N. Luponosov, M. Kraft, S.A. Ponomarenko, T. Ameri, U. Scherf and C. J. Brabec. A combination of Al-doped ZnO and a conjugated polyelectrolyte interlayer for small molecule solution-processed solar cells with an inverted structure, J. Mater. Chem. A 1(37), 2013, 11306. [Web of Science]

            • [6] L. Grządziel, M. Krzywiecki, H. Peisert, T. Chassé and J. Szuber, Photoemission study of the Si(1 1 1)-native SiO2/copper phthalocyanine (CuPc) ultra-thin film interface, Organic Electr. 13(10), 2012, 1873.

            • [7] Y. Gao, Surface analytical studies of interfaces in organic semiconductor devices, Materials Science and Engineering R: Reports 68(3), 2010, 39.

            • [8] J. L. Brédas and A. J. Heeger, Influence of Donor and Acceptor Substituents on the Electronic Characteristics of Poly(Paraphenylene Vinylene) and Poly(Paraphenylene), Chem. Phys. Lett. 217, 1994, 507.

            • [9] F. Babudri, G. M. Farinola, F. Naso and R. Ragni, Fluorinated Organic Materials for Electronic and Optoelectronic Applications: The Role of the Fluorine Atom, Chem. Comm. 10, 2007, 1003. [Crossref]

            • [10] J. Cornil, D. A. Dos Santos, D. Beljonne and J. L. Bredas, Electronic Structure of Phenylene Vinylene Oligomers: Influence of Donor/Acceptor Substitutions, J. Phys. Chem. 99, 1995, 5604.

            • [11] Y. Fu, W. Shen and M Li, Theoretical Analysis on the Electronic Structures and Properties of PPV Fused with Electron- Withdrawing Unit: Monomer, Oligomer and Polymer, Polymer 49, 2008, 2614. [Web of Science]

            • [12] A. P. Hitchcock, P. Fischer, A. Gedanken and M. B. Robin, Antibonding Sigma* ValenceMOs in the Inner-Shell and Outer-Shell Spectra of the Fluorobenzenes, J. Phys. Chem. 91, 1987, 531.

            • [13] R. Dudde, B. Reihl and A. Otto, π* and σ* molecular orbitals of condensed films of chlorobenzenes and hexafluorobenzene observed by inverse photoemission J. Chem. Phys. 92(6), 1990, 3930.

            • [14] A. Modelli, Electron Attachment and Intramolecular Electron Transfer in Unsaturated Chloroderivatives, Phys. Chem. Chem. Phys. 5, 2003, 2923. [Crossref]

            • [15] S. A. Pshenichnyuk, N. L. Asfandiarov and P. D. Burrow, A Relation Between Energies of the Short-Lived Negative Ion States and Energies of Unfilled Molecular Orbitals for a Series of Bromoalkanes, Russ. Chem. Bull., Int. Ed. 56, 2007, 1268. [Web of Science]

            • [16] A. S. Komolov, P. J. Møller and E. F. Lazneva, Interface Formation Between Oligo(Phenylele–Vinylene) Films and Highly Ordered Pyrolytic Graphite and Ge(1 1 1) Surfaces, J. Electron Spectr. Rel. Phenom. 131-132, 2003, 67.

            • [17] A. S. Komolov, E. F. Lazneva, S. N. Akhremtchik, N. S. Chepilko and A. A. Gavrikov, Unoccupied Electronic States at the Interface of Oligo(phenylene-vinylene) Films with Oxidized Silicon, J. Phys. Chem. C, 117(24), 2013, 12633.

            • [18] J. Ren, Sh. Meng, Y-L. Wang, X-C. Ma, Q-K. Xue and E. Kaxiras, Properties of Copper (Fluoro) Phthalocyanine Layers Deposited on Epitaxial Graphene, J. Chem. Phys. 134, 2011, 194706.

            • [19] S. Godlewski, A. Tekiel, J.S. Prauzner-Bechcicki, J. Budzioch, A. Gourdon and M. Szymonski, Adsorption of organicmolecules on the TiO2(011) surface: STM study, J. Chem. Phys. 134(22), 2011, 224701.

            • [20] A. Opitz, B. Ecker, J. Wagner, A. Hinderhofer, F. Schreiber, J. Manara, J. Pflaum and W. Brütting, Mixed crystalline films of co-evaporated hydrogen- and fluorine-terminated phthalocyanines and their application in photovoltaic devices, Organic Electr. 10, 2009, 1259.

            • [21] A. S. Komolov, P. J. Møller, J. Mortensen, S. A. Komolov and E. F. Lazneva, Modification of the electronic properties of the TiO2 (1 1 0) surface upon deposition of the ultrathin conjugated organic layers, Appl. Surf. Sci. 253, 2007, 7376.

            • [22] A. S. Komolov, S. A. Komolov, E. F. Lazneva, A. A. Gavrikov and A. M. Turiev, Electronic properties of the polycrystalline tin dioxide interface with conjugated organic layers, Surf. Sci. 605, 2011, 1449.

            • [23] A. S. Komolov, E. F. Lazneva, S. A. Pshenichnyuk, A. A. Gavrikov, N. S. Chepilko, A. A. Tomilov, N. B. Gerasimova, A. A. Lezov and P. S. Repin, Electronic properties of the interface between hexadecafluoro copper phthalocyanine and unsubstituted copper phthalocyanine films, Semiconductors 47(7), 2013, 956. [Web of Science] [Crossref]

            • [24] I. Bartos, Electronic structure of crystals via VLEED, Progr. Surf. Sci. 59, 1998, 197.

            • [25] S.A. Pshenichnyuk and A.S.Komolov, Relation between Electron Scattering Resonances of Isolated NTCDA Molecules and Maxima in the Density of Unoccupied States of Condensed NTCDA Layers, J. Phys. Chem. A 116 (1), 2012, 761. [Web of Science]

            • [26] M. J. Frisch, G.W. Trucks, H. B. Schlegel et al., Gaussian 03.D.01, Gaussian Inc. Wallingford CT, 2004.

            • [27] A. D. Becke, Density functional thermochemistry. III. The role of exact exchange, J. Chem. Phys. 98, 1993, 5648.

            • [28] I. G. Hill, A. Kahn, J. Cornil, D.A. dos Santos and J.L. Bredas, Occupied and unoccupied electronic levels in organic piconjugated molecules: comparison between experiment and theory, Chem. Phys. Lett. 317, 2000, 444.

            • [29] P. D. Burrow and A. Modelli, On the treatment of LUMO energies for their use as descriptors, SAR and QSAR in Env. Res. 24(8), 2013, 647. [Web of Science]

            • [30] A. Modelli and S.A. Pshenichnyuk, Empty-Level Structure and Reactive Species Produced by Dissociative Electron Attachment to Tert -Butyl Peroxybenzoate, J. Phys. Chem. A 116(14), 2012, 3585.

            • [31] A. M. Scheer and P. D. Burrow, π* Orbital System of Alternating Phenyl and Ethynyl Groups: Measurements and Calculations, J. Phys. Chem. B 110(36), 2006, 17751.

            • [32] S. A. Pshenichnyuk, A. V. Kukhto, I.N. Kukhto and A. S. Komolov, Spectroscopic States of PTCDA Negative Ions and Their Relation to the Maxima of Unoccupied State Density in the Conduction Band, Technical Phys. 56, 2011, 754. [Web of Science]

            • [33] A. S. Komolov, S. N. Akhremtchik and E. F. Lazneva, Spectrochim. Acta A 798, 2011, 708.

            • [34] H. Yoshida, K. Tsutsumi and N. Sato, Unoccupied electronic states of 3d-transition metal phthalocyanines (MPc: M=Mn, Fe, Co, Ni, Cu and Zn) studied by inverse photoemission spectroscopy, J. El. Spectr. Rel. Phen. 121, 2001, 83.

            • [35] H. Peisert, T. Schwieger, J. M. Auerhammer, M. Knupfer, M. S. Golden, J. Fink, P. R. Bressler and M. Mast, Order on disorder: Copper phthalocyanine thin films on technical substrates, J. Appl. Phys. 90(1) 2001, 466. [Crossref]

            • [36] M. Rocco, K. Frank, P. Yannoulis and E. Koch, Unoccupied electronic structure of phthalocyanine films. J. Chem. Phys. 93(9), 1990, 6859.

            About the article

            Received: 2014-09-01

            Accepted: 2014-12-19

            Published Online: 2015-01-29

            Citation Information: Organic Photonics and Photovoltaics, ISSN (Online) 2299-3177, DOI: https://doi.org/10.1515/oph-2015-0002. Export Citation

            ©2015 A. S. Komolov et al.. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. (CC BY-NC-ND 3.0)

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