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Jensen IJT, Gorantla S, Løvvik OM, Gan J, Nguyen PD, Monakhov E, Svensson BG, Gunnæs AE, Diplas S. Interface phenomena in magnetron sputtered Cu 2O/ZnO heterostructures. J Phys Condens Matter 2017; 29:435002. [PMID: 28829336 DOI: 10.1088/1361-648x/aa8799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The interface between ZnO and Cu2O has been predicted to be a good candidate for use in thin film solar cells. However, the high predicted conversion efficiency has yet to be fully realized experimentally. To explore the underlying causes of this we investigate the interface between ZnO and Cu2O in magnetron sputtered samples. Two different sample geometries were made: In the first set thin layers of ZnO were deposited on Cu2O (type A), while in the second set the order was reversed (type B). Using x-ray photoelectron spectroscopy (XPS), an intermediate CuO layer was identified regardless of the order in which the Cu2O and ZnO layers were deposited. The presence of a CuO layer was supported by transmission electron microscopy (TEM) results. Changes in the electron hole screening conditions were observed in CuO near the interface with ZnO, manifested as changes in the relative peak-to-satellite ratio and the degree of asymmetric broadness in the Cu 2p peak. The suppression of the Cu 2p satellite characteristic of CuO may cause the CuO presence to be overlooked and cause errors in determinations of valence band offsets (VBOs). For the type A samples, we compare four different approaches to XPS-based determination of VBO and find that the most reliable results are obtained when the thin CuO layer and the altered screening conditions at the interface were taken into account. The VBOs were found to range between 2.5 eV and 2.8 eV. For the B type samples a reduction of the Cu 2p-LMM Auger parameter was found as compared to bulk Cu2O, indicative of quantum confinement in the Cu2O overlayer.
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Affiliation(s)
- I J T Jensen
- SINTEF Materials and Chemistry, P/O box 124 Blindern, 0314 Oslo, Norway
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Angelopoulos PM, Maliachova C, Papakonstantinou K, Taxiarchou M, Diplas S. Structural and physical characteristics of fine perlite expanded with a novel method in a vertical electric furnace. ACTA ACUST UNITED AC 2016. [DOI: 10.1080/03719553.2016.1156244] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Affiliation(s)
- I. J. T. Jensen
- Department of Physics; University of Oslo; P/O box 1048 Blindern; 0316; Oslo; Norway
| | | | - H. Schreuders
- Materials for Energy Conversion or Storage (MECS), DelftChemTech, Faculty of Applied Science; Technical University Delft; P/O Box 5045; NL-2600; GA; Delft; The Netherlands
| | - B. Dam
- Materials for Energy Conversion or Storage (MECS), DelftChemTech, Faculty of Applied Science; Technical University Delft; P/O Box 5045; NL-2600; GA; Delft; The Netherlands
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Tsiourvas D, Tsetsekou A, Arkas M, Diplas S, Mastrogianni E. Covalent attachment of a bioactive hyperbranched polymeric layer to titanium surface for the biomimetic growth of calcium phosphates. J Mater Sci Mater Med 2011; 22:85-96. [PMID: 21069559 PMCID: PMC3019359 DOI: 10.1007/s10856-010-4181-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Accepted: 10/25/2010] [Indexed: 05/30/2023]
Abstract
This work is investigating the chemical grafting on Ti surface of a polymer/calcium phosphate coating of improved adhesion for enhanced bioactivity. For this purpose, a whole new methodology was developed based on covalently attaching a hyperbranched poly(ethylene imine) layer on Ti surface able to promote calcium phosphate formation in a next deposition stage. This was achieved through an intermediate surface silanization step. The research included optimization both of the reaction conditions for covalently grafting the intermediate organosilicon and the subsequent hyperbranched poly(ethylene imine) layers, as well as of the conditions for the mechanical and chemical pretreatment of Ti surface before coating. The reaction steps were monitored employing FTIR and XPS analyses, whereas the surface morphology and structure of the successive coating layers were studied by SEM combined with EDS. The analysis confirmed the successful grafting of the hybrid layer which demonstrated very good ability for hydroxyapatite growth in simulated body fluid.
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Affiliation(s)
- D. Tsiourvas
- Institute of Physical Chemistry, NCSR “Demokritos”, 15310 Aghia Paraskevi, Attiki, Greece
| | - A. Tsetsekou
- School of Mining Engineering and Metallurgy, National Technical University of Athens, Iroon Polytechniou, Zografou Campus, 15780 Athens, Greece
| | - M. Arkas
- Institute of Physical Chemistry, NCSR “Demokritos”, 15310 Aghia Paraskevi, Attiki, Greece
| | - S. Diplas
- SINTEF Materials and Chemistry, Forskningsvn 1, NO-0314 Oslo, Norway
- Department of Chemistry and Centre for Materials Science and Nanotechnology (SMN), University of Oslo, P.O. Box 1033, Blindern, NO-0315 Oslo, Norway
| | - E. Mastrogianni
- School of Mining Engineering and Metallurgy, National Technical University of Athens, Iroon Polytechniou, Zografou Campus, 15780 Athens, Greece
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Jensen IJT, Diplas S, Løvvik OM, Watts J, Hinder S, Schreuders H, Dam B. X-ray photoelectron spectroscopy study of MgH2
thin films grown by reactive sputtering. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Sunding MF, Kepaptsoglou DM, Diplas S, Norby T, Gunnaes AE. XPS characterisation of the interface between anode and electrolyte in a proton conducting solid oxide fuel cell. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3383] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Diplas S, Moslemzadeh N, Watts JF, Beamson G, Tsakiropoulos P. An XPS study of the interatomic charge distribution in stainless steels. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Diplas S, Løvvik OM, Nordmark H, M Kepaptsoglou D, Graff JM, Ladam C, Tyholdt F, Walmsley JC, Gunnaes AE, Fagerberg R, Ulyashin A. Characterization of thin and ultrathin transparent conducting oxide (TCO) films and TCO-Si interfaces with XPS, TEM and ab initio modeling. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3355] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Diplas S, Løvvik OM. Electronic structure studies of Ni-X (X: B, S, P) alloys using x-ray photoelectron spectroscopy, x-ray induced Auger electron spectroscopy and density functional theory calculations. J Phys Condens Matter 2009; 21:245503. [PMID: 21693949 DOI: 10.1088/0953-8984/21/24/245503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The electronic structure of Ni-X (X = B, S, P) alloys was studied using x-ray photoelectron spectroscopy, x-ray induced Auger electron spectroscopy and density functional theory. The spectroscopic data in the form of the Ni 2p shake-up satellite and the Ni 2p LMM, P 2p KLL and S 2p KLL Auger parameters combined with density of states (DOS) and charge difference plots suggest an overall charge transfer from the Ni sites towards the alloying addition sites. However, this is masked, with intra-atomic charge redistribution leading to an increased occupancy of the Ni 3d states in the alloys. The Ni 3d DOS shows strong similarity to that of Pt which is the best catalyst for hydrogen evolution.
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Diplas S, Knutsen T, Jørgensen S, Gunnæs AE, Våland T, Norby T, Olsen A, Taftø J. An experimental study of the electronic structure of anodically grown films on an amorphous Ni78Si8B14 alloy. SURF INTERFACE ANAL 2008. [DOI: 10.1002/sia.2748] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Diplas S, Prytz O, Karlsen OB, Watts JF, Taftø J. A quantitative study of valence electron transfer in the skutterudite compound CoP(3) by combining x-ray induced Auger and photoelectron spectroscopy. J Phys Condens Matter 2007; 19:246216. [PMID: 21694059 DOI: 10.1088/0953-8984/19/24/246216] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We use the sum of the ionization and Auger energy, the so-called Auger parameter, measured from the x-ray photoelectron spectrum, to study the valence electron distribution in the skutterudite CoP(3). The electron transfer between Co and P was estimated using models relating changes in Auger parameter values to charge transfer. It was found that each P atom gains 0.24 e(-), and considering the unit formula CoP(3) this is equivalent to a donation of 0.72 e(-) per Co atom. This is in agreement with a recent electron energy-loss spectroscopy study, which indicates a charge transfer of 0.77 e(-)/atom from Co to P.
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Affiliation(s)
- S Diplas
- Centre for Materials Science and Nanotechnology, University of Oslo, PO Box 1126, Blindern, NO-0318 Oslo, Norway. Department of Physics, University of Oslo, PO Box 1048, Blindern, NO-0316 Oslo, Norway
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Diplas S, Lehrmann J, Jørgensen S, Våland T, Watts JF, Taftø J. Characterization of NiB amorphous alloys with x-ray photoelectron and secondary ion mass spectroscopy. SURF INTERFACE ANAL 2005. [DOI: 10.1002/sia.2033] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Mitchell T, Diplas S, Tsakiropoulos P, Watts JF, Matthew JAD. Study of alloying behaviour in metastable Mg-Ti solid solutions using Auger parameter measurements and charge-transfer calculations. ACTA ACUST UNITED AC 2002. [DOI: 10.1080/01418610208243206] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Diplas S, Watts JF, Tsakiropoulos P, Shao G, Beamson G, Matthew JAD. X-ray photoelectron spectroscopy studies of Ti-Al and Ti-Al-V alloys using Cr K? radiation. SURF INTERFACE ANAL 2001. [DOI: 10.1002/sia.1103] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Diplas S, Tsakiropoulos P, Brydson RMD, Watts JF. A study of charge transfer in vapour deposited Mg—V crystalline alloys via changes in Auger parameters. ACTA ACUST UNITED AC 1998. [DOI: 10.1080/01418619808221229] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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