Ola Nilsen

• Bratvold, Jon E.; Fjellvåg, Helmer & Nilsen, Ola (2020). Phase and Orientation Control of NiTiO3 Thin Films. Materials.  ISSN 1996-1944.  13(1), s 1- 19 . doi: 10.3390/ma13010112
• Brennhagen, Anders; Kvamme, Kristian Breivik; Sverdlilje, Katja S. S. & Nilsen, Ola (2020). High power iron phosphate cathodes by atomic layer deposition. Solid State Ionics.  ISSN 0167-2738.  353 . doi: 10.1016/j.ssi.2020.115377 Fulltekst i vitenarkiv. Vis sammendrag

  Amorphous thin films of FePO4 and Fe4(P2O7)3 show excellent power capabilities and good stability as cathode materials in Li-ion batteries. Within our tested range of materials, 10 nm FePO4 shows the best results and can handle specific powers above 1 MW/kg. The thin films are deposited using atomic layer deposition (ALD) and we studied the growth using in situ quartz crystal microbalance (QCM) showing self-limiting growth. Their electrochemical properties were characterized as cathode materials in coin cell batteries using cyclic voltammetry (CV) and galvanostatic cycling (GC), correcting for the roughness of the substrates and addressing contributions from non-Faradaic processes.

• Cheng, Chaoqun; Akram, Muhammad Nadeem; Nilsen, Ola; Pryds, Nini & Wang, Kaiying (2020). Solar-driven plasmonic heterostructure Ti/TiO2−x with gradient doping for sustainable plasmon-enhanced catalysis. Physical Chemistry, Chemical Physics - PCCP.  ISSN 1463-9076.  22(15), s 7769- 7777 . doi: 10.1039/d0cp00672f Vis sammendrag

  Plasmon-enhanced harvesting of photons has contributed to the photochemical conversion and storage of solar energy. However, high dependence on noble metals and weak coupling in heterostructures constrain the progress towards sustainable plasmonic enhancement. Here earth-abundant Ti is studied to achieve the plasmonic enhancement of catalytic activity in a solar-driven heterostructure Ti/TiO2−x. The heterostructure was fabricated by engineering an intense coupling of a surface-etched Ti metal and a gradient-based TiO2−x dielectric via diffusion doping. Ti/TiO2−x exhibits a highly resonant light absorption band associated with surface plasmon resonances that exhibit strong near-field enhancement (NFE) and hot electron injection effects. In a photoelectrochemical system, intense interaction of the resonant plasmons with a vicinal TiO2−x dielectric accelerates the transfer of solar energy to charge carriers for plasmon-enhanced water splitting reactions. Moreover, the plasmonic Ti/TiO2−x structure presents sustained enhanced redox activities over 100 h. The intense coupling by gradient doping offers an effective approach to enable the plasmon resonances of Ti excited by visible light. The Ti-based plasmonic heterostructure potentially opens an alternative avenue towards sustainable plasmon-enhanced catalysis.

• Duparc, Marion Jeanne Louise; Sønsteby, Henrik Hovde; Nilsen, Ola; Sjåstad, Anja Olafsen & Fjellvåg, Helmer (2020). Atomic Layer Deposition of GdCoO3 and Gd0.9Ca0.1CoO3. Materials.  ISSN 1996-1944.  13(1), s 1- 10 . doi: 10.3390/ma13010024 Fulltekst i vitenarkiv.
• Ellingsen, Josef Gert Åsheim; Venkatachalapathy, Vishnukanthan; Azarov, Alexander; Nilsen, Ola & Kuznetsov, Andrej (2020). Al incorporation during metal organic chemical vapour deposition of aluminium zinc oxide. Thin Solid Films.  ISSN 0040-6090.  709 . doi: 10.1016/j.tsf.2020.138245
• Fjellvåg, Øystein; Ruud, Amund; Sønsteby, Henrik Hovde; Nilsen, Ola & Fjellvåg, Helmer (2020). Crystallization, Phase Stability, and Electrochemical Performance of β-MoO3 Thin Films. Crystal Growth & Design.  ISSN 1528-7483.  20(6), s 3861- 3866 . doi: 10.1021/acs.cgd.0c00156 Vis sammendrag

  Insight into the crystallization process of functional materials deposited as thin films in an amorphous state is essential when phase pure samples of specific polymorphs are sought for utilization of performance aspects or fundamental studies. In this work, we report on controlled crystallization of α- and β-MoO3 polymorphs from amorphous MoO3 thin films produced by atomic layer deposition (ALD). The MoO3 films are amorphous as deposited. Our experiments show that β-MoO3 starts to crystallize from amorphous MoO3 at a surprisingly low temperature of 185 °C, only 20 °C above the adopted ALD deposition temperature. Thin films of the β-MoO3 polymorph start to slowly convert into α-MoO3 at temperatures above 300 °C; however, long holding times are required to obtain phase pure products. High-quality thin film samples (electrodes) were characterized by electrochemical cycling toward lithium, demonstrating that α- and β-MoO3 transfers into the same chemical state during cycling and that amorphous MoO3 undergoes less change upon cycling.

• Hansen, Per-Anders Stensby; Zikmund, Tomas; Yu, Ting; Kvalvik, Julie Nitsche; Aarholt, Thomas; Prytz, Øystein; Meijerink, Andries & Nilsen, Ola (2020). Single-step approach to sensitized luminescence through bulk-embedded organics in crystalline fluorides. Communications chemistry.  ISSN 2399-3669.  3 . doi: 10.1038/s42004-020-00410-0 Fulltekst i vitenarkiv.
• Hu, Yang; Miikkulainen, Ville; Mizohata, Kenichiro; Norby, Truls Eivind; Nilsen, Ola & Fjellvåg, Helmer (2020). Ionic conductivity in LixTaOy thin films grown by Atomic Layer Deposition (ALD). Electrochimica Acta.  ISSN 0013-4686.  361 . doi: 10.1016/j.electacta.2020.137019
• Kjeldstad, Torunn; Thøgersen, Annett; Stange, Marit Synnøve Sæverud; Jensen, Ingvild Julie Thue; Nilsen, Ola; Galeckas, Augustinas & Monakhov, Eduard (2020). Selective etching of nanostructured a-Si:Al and its effect on porosity, Al gradient and surface oxidation. Thin Solid Films.  ISSN 0040-6090.  702 . doi: 10.1016/j.tsf.2020.137982 Fulltekst i vitenarkiv. Vis sammendrag

  Nanoporous amorphous silicon (a-Si) with <5 nm cylindrical pores have been fabricated by phase separation of aluminum (Al) and silicon, forming self-assembled Al nanowires (NWs), followed by subsequent removal of Al by wet etching. This work studies the removal process of the Al NWs when using the different etchants HCl, H3PO4, and H2SO4. Total reflectance measurements are used in combination with theoretical modeling to estimate the lateral gradient of Al concentration formed during the etching process. X-ray Photoelectron Spectroscopy is used to show that the choice of Al etching agent has implications for the surface states of the remaining a-Si matrix. We have found that H3PO4 is the most efficient etching agent, while HCl provides a less oxidized a-Si matrix in addition to the least reflective surface. By varying the etching agent, the degree of surface oxidation and shape of Al gradient throughout the film can be tuned.

• Kvalvik, Julie Nitsche; Hansen, Per-Anders Stensby & Nilsen, Ola (2020). Design of experiments approach to luminescent CaMoO4 by atomic layer deposition. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films.  ISSN 0734-2101.  38, s 052408 . doi: 10.1116/6.0000327
• Kvalvik, Julie Nitsche; Kvamme, Kristian Breivik; Almaas, Kjetil; Ruud, Amund; Sønsteby, Henrik Hovde & Nilsen, Ola (2020). LiF by atomic layer deposition—Made easy. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films.  ISSN 0734-2101.  38(5), s 1- 4 . doi: 10.1116/6.0000314
• Lausund, Kristian Blindheim; Olsen, Malin; Hansen, Per-Anders Stensby; Valen, Håkon & Nilsen, Ola (2020). MOF thin films with bi-aromatic linkers grown by molecular layer deposition. Journal of Materials Chemistry A.  ISSN 2050-7488.  8(5), s 2539- 2548 . doi: 10.1039/c9ta09303f
• Sønsteby, Henrik Hovde; Bratvold, Jon Einar; Killi, Veronica Anne-Line Kathrine; Choudhury, Devika; Elam, Jeffrey W.; Fjellvåg, Helmer & Nilsen, Ola (2020). tert-butoxides as precursors for atomic layer deposition of alkali metal containing thin films. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films.  ISSN 0734-2101.  38, s 1- 15 . doi: 10.1116/6.0000589 Fulltekst i vitenarkiv.
• Sønsteby, Henrik Hovde; Killi, Veronica Anne-Line Kathrine; Storaas, Thomas Aarflot; Choudhuy, Devika; Elam, Jeffrey W.; Fjellvåg, Helmer & Nilsen, Ola (2020). Understanding KOtBu in atomic layer deposition–in situ mechanistic studies of the KNbO3 growth process. Dalton Transactions.  ISSN 1477-9226. . doi: 10.1039/D0DT02324H
• Sønsteby, Henrik Hovde; Skaar, Erik; Bratvold, Jon Einar; Freeland, John W.; Yanguas-Gil, Angel; Elam, Jeffrey W.; Nilsen, Ola & Fjellvåg, Helmer (2020). Tuning electronic properties in LaNiO3 thin films by B-site Cu-substitution. Journal of Materials Chemistry C.  ISSN 2050-7526.  8, s 12662- 12668 . doi: 10.1039/D0TC03406A
• Sønsteby, Henrik Hovde; Skaar, Erik; Fjellvåg, Øystein; Bratvold, Jon E.; Fjellvåg, Helmer & Nilsen, Ola (2020). A foundation for complex oxide electronics -low temperature perovskite epitaxy. Nature Communications.  ISSN 2041-1723.  11(1) . doi: 10.1038/s41467-020-16654-2 Fulltekst i vitenarkiv.
• Bratvold, Jon E.; Sønsteby, Henrik Hovde; Nilsen, Ola & Fjellvåg, Helmer (2019). Control of growth orientation in as-deposited epitaxial iron-rich nickel ferrite spinel. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films.  ISSN 0734-2101.  37(2), s 1- 7 . doi: 10.1116/1.5082012 Fulltekst i vitenarkiv.
• Getz, Michael; Nilsen, Ola & Hansen, Per-Anders Stensby (2019). Sensors for optical thermometry based on luminescence from layered YVO4: Ln3+ (Ln = Nd, Sm, Eu, Dy, Ho, Er, Tm, Yb) thin films made by atomic layer deposition. Scientific Reports.  ISSN 2045-2322.  9(1) . doi: 10.1038/s41598-019-46694-8
• Hansen, Per-Anders Stensby; Granerød, Cecilie Skjold; Prytz, Øystein & Nilsen, Ola (2019). Controlling luminescence and quenching mechanisms in subnanometer multilayer structure of europium titanate thin films. Journal of Luminescence.  ISSN 0022-2313.  215 . doi: 10.1016/j.jlumin.2019.116618 Fulltekst i vitenarkiv.
• Momtazi, Leva; Sønsteby, Henrik Hovde & Nilsen, Ola (2019). Biocompatible organic-inorganic hybrid materials based on nucleobases and titanium developed by molecular layer deposition. Beilstein Journal of Nanotechnology.  ISSN 2190-4286.  10(1), s 399- 411 . doi: 10.3762/bjnano.10.39 Fulltekst i vitenarkiv.
• Sønsteby, Henrik Hovde; Nilsen, Ola & Fjellvåg, Helmer (2019). Chemical Uniformity in Ferroelectric KxNa1−xNbO3 Thin Films. Global Challenges.  ISSN 2056-6646.  3(10), s 1800114 . doi: 10.1002/gch2.201800114 Fulltekst i vitenarkiv.
• Zhang, Zengxing; Wang, Yonghua; Hansen, Per-Anders Stensby; Du, Kang; Gustavsen, Kim Robert; Liu, Guohua; Karlsen, Frank; Nilsen, Ola; Xue, Chenyang & Wang, Kaiying (2019). Black silicon with order-disordered structures for enhanced light trapping and photothermic conversion. Nano Energy.  ISSN 2211-2855.  65, s 1- 8 . doi: 10.1016/j.nanoen.2019.103992 Vis sammendrag

  Black silicon has become a versatile substrate for photoelectric and photothermic application due to its excellent light trapping ability. However, subsequent material engineering can conflict with its intrinsic anti-reflective behavior. In this paper, we present a two-step etching approach to create novel black silicon combining ordered micropores and disordered nanopores. The larger pores increase the optical path length and provide space to load functional materials, while the smaller ones facilitate coupling between the incident solar radiation and material. The proposed etching method increases the light-trapping ability of conventional nanostructured black silicon and achieves enhanced absorption in a broad spectrum. Besides, loading Au nanoparticles further improve the light absorbance in the near-infrared range of 1100–1700 nm. The intrinsic SiOx-rich layer on silicon surface produced during SF6/O2 plasma etching leads to photothermic conversion being the dominant dissipation route for the light energy, thereby yielding outstanding performance in photothermic and photo-thermal-electric demonstrations. This work establishes a robust relationship between three-dimensional structure and light-trapping property of black silicon and provides insights into substrate designs that facilitate the light conversion.

• Dziadkowiec, Joanna; Javadi, Shaghayegh; Bratvold, Jon E.; Nilsen, Ola & Røyne, Anja (2018). Surface Forces Apparatus Measurements of Interactions between Rough and Reactive Calcite Surfaces. Langmuir.  ISSN 0743-7463.  34((25)), s 7248- 7263 . doi: 10.1021/acs.langmuir.8b00797 Fulltekst i vitenarkiv.
• Momtazi, Leva; Dartt, Darlene Ann; Nilsen, Ola & Eidet, Jon Roger (2018). Molecular layer deposition builds biocompatible substrates for epithelial cells. Journal of Biomedical Materials Research. Part A.  ISSN 1549-3296.  106(12), s 3090- 3098 . doi: 10.1002/jbm.a.36499
• Sønsteby, Henrik Hovde; Aarholt, Thomas; Prytz, Øystein; Fjellvåg, Helmer & Nilsen, Ola (2018). First Complex Oxide Superconductor by Atomic Layer Deposition. Chemical Communications.  ISSN 1359-7345.  54(59), s 8253- 8256 . doi: 10.1039/c8cc04998j
• Sønsteby, Henrik Hovde; Bratvold, Jon E.; Weibye, Kristian; Fjellvåg, Helmer & Nilsen, Ola (2018). Phase Control in Thin Films of Layered Cuprates. Chemistry of Materials.  ISSN 0897-4756.  30(3), s 1095- 1101 . doi: 10.1021/acs.chemmater.7b05005
• Vajeeston, Ponniah; Fjellvåg, Helmer & Nilsen, Ola (2018). Search for potential precursors for Si-atomic layer deposition- a quantum chemical study. Materials Letters.  ISSN 0167-577X.  216, s 189- 192 . doi: 10.1016/j.matlet.2018.01.040 Fulltekst i vitenarkiv. Vis sammendrag

  Thin film of silicon is an interesting material for many technological applications in electronic industry and in energy harvesting technologies, but requires a method for controlled growth of thin films. The purpose of this study is to screen a wide variety of Si content precursors for Si atomic layer deposition (ALD) reactions using state-of-the-art density-functional calculations. Among the studied 85 Si content precursors we found that C7H12OSi–Methoxy-trivinyl-silane and C7H9NSi–Benzyliminosilane show positive indications for ALD reactivity for Si deposition. We believe that this finding will be helpful to develop low-cost, high-energy efficiency thin-film solar cells for future scale up implementation in photovoltaics.

• Ferreira, Ana RV; Haapanen, Janne; Makela, Jyrki M; Bratvold, Jon E.; Nilsen, Ola; Tuominen, Mikko; Alves, Vitor D & Coelhoso, Isabel M (2017). Comparison of different coating techniques on the properties of FucoPol films. International Journal of Biological Macromolecules.  ISSN 0141-8130.  103, s 268- 274 . doi: 10.1016/j.ijbiomac.2017.05.021
• Getz, Michael; Hansen, Per-Anders Stensby; Fjellvåg, Øystein Slagtern; Ahmed, Mohammed Amin Karim; Fjellvåg, Helmer & Nilsen, Ola (2017). Intense NIR emission in YVO4:Yb3+ thin films by atomic layer deposition. Journal of Materials Chemistry C.  ISSN 2050-7526.  5(33), s 8572- 8578 . doi: 10.1039/c7tc02135f Fulltekst i vitenarkiv.
• Getz, Michael; Hansen, Per-Anders; Ahmed, Mohammed Amin Karim; Fjellvåg, Helmer & Nilsen, Ola (2017). Luminescent YbVO4 by atomic layer deposition. Dalton Transactions.  ISSN 1477-9226.  46(9), s 3008- 3013 . doi: 10.1039/c7dt00253j Fulltekst i vitenarkiv.
• Getz, Michael; Hansen, Per-Anders; Fjellvåg, Helmer & Nilsen, Ola (2017). Luminescent properties of europium titanium phosphate thin films deposited by atomic layer deposition. RSC Advances.  ISSN 2046-2069.  7(13), s 8051- 8059 . doi: 10.1039/c6ra27644j Fulltekst i vitenarkiv.
• Kjeldstad, Torunn; Thøgersen, Annett; Nilsen, Ola; Monakhov, Edouard & Galeckas, Augustinas (2017). Controllable template approach for ZnO nanowire growth. Physica Status Solidi (a) applications and materials science.  ISSN 1862-6300.  214(2), s 1- 6 . doi: 10.1002/pssa.201600480 Vis sammendrag

  Anodic aluminum oxide (AAO) is an optically transparent material with uniform hexagonal pores, which has widely been used as a template for nanowire growth. This study examines the potential of utilizing commercially available AAO to fabricate sub-10 nm ZnO nanowires by atomic layer deposition. The pore diameter of the AAO framework is reduced by controlled deposition of . Subsequently, ZnO is deposited and ZnO nanowires are obtained. The analysis of structural and optical properties shows that the nanowires are polycrystalline, and exhibit a pronounced near band edge emission. Photoluminescence (PL) measurements are performed to monitor the effect of additional coating with and ZnO, on the optical stability of the AAO. The measurements indicate that the PL is highly influenced by the adsorption and desorption of species from the ambient at the surface. ALD deposition of a thin layer reduces considerably the effect of ambient atmosphere. The layer of facilitates PL characterization of very thin ZnO nanowires.

• Lausund, Kristian Blindheim; Petrovic, Veljko & Nilsen, Ola (2017). All-gas-phase synthesis of amino-functionalized UiO-66 thin films. Dalton Transactions.  ISSN 1477-9226.  46(48), s 16983- 16992 . doi: 10.1039/c7dt03518g
• Momtazi, Leva; Sønsteby, Henrik Hovde; Dartt, DA; Eidet, Jon Roger & Nilsen, Ola (2017). Bioactive titaminates from molecular layer deposition. RSC Advances.  ISSN 2046-2069.  7(34), s 20900- 20907 . doi: 10.1039/C7RA01918A Fulltekst i vitenarkiv.
• Napari, M; Tarvainen, O; Kinnunen, S; Arstila, K; Julin, J; Fjellvåg, Øystein Slagtern; Weibye, Kristian; Nilsen, Ola & Sajavaara, T (2017). The α and γ plasma modes in plasma-enhanced atomic layer deposition with O2-N2 capacitive discharges. Journal of Physics D: Applied Physics.  ISSN 0022-3727.  50(9) . doi: 10.1088/1361-6463/aa59b3 Fulltekst i vitenarkiv.
• Ruud, Amund; Miikkulainen, Ville; Mizohata, Kenichiro; Fjellvåg, Helmer & Nilsen, Ola (2017). Enhanced process and composition control for atomic layer deposition with lithium trimethylsilanolate. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films.  ISSN 0734-2101.  35(1) . doi: 10.1116/1.4972209
• Sønsteby, Henrik Hovde; Fjellvåg, Helmer & Nilsen, Ola (2017). Functional perovskites by atomic layer deposition - an overview. Advanced Materials Interfaces.  ISSN 2196-7350.  4:1600903, s 1- 15 . doi: 10.1002/admi.201600903
• Sønsteby, Henrik Hovde; Weibye, Kristian; Bratvold, Jon E. & Nilsen, Ola (2017). Rubidium containing thin films by atomic layer deposition. Dalton Transactions.  ISSN 1477-9226.  46(46), s 16139- 16144 . doi: 10.1039/c7dt03753h
• Samarasingha, Pushpaka; Sottmann, Jonas; Margadonna, Serena; Emerich, Hermann; Nilsen, Ola & Fjellvåg, Helmer (2016). In situ synchrotron study of ordered and disordered LiMn1.5Ni0.5O4 as lithium ion battery positive electrode. Acta Materialia.  ISSN 1359-6454.  116, s 290- 297 . doi: 10.1016/j.actamat.2016.06.040
• Gandrud, Knut Bjarne; Nilsen, Ola & Fjellvåg, Helmer (2016). Ultra-high power capabilities in amorphous FePO4 thin films. Journal of Power Sources.  ISSN 0378-7753.  306, s 454- 458 . doi: 10.1016/j.jpowsour.2015.12.024
• Gustavsen, Kim Robert; Nygård, Ken Alexander; Honerød-Bentsen, Preben; Du, Kang; Liu, Guohua; Tayyib, Muhammad; Breiby, Dag Werner; Weibye, Kristian; Nilsen, Ola; Aasmundtveit, Knut Eilif & Wang, Kaiying (2016). Wafer-level fabrication and characterization of amorphous thin films MoS2 prepared by RF magnetron sputtering technique. ECS Transactions.  ISSN 1938-5862.  75(13), s 131- 137 . doi: 10.1149/07513.0131ecst Vis sammendrag

  In this paper, we present a study of wafer-level process for deposition of amorphous thin film MoS2 by radio-frequency (RF) magnetron sputtering technique. Thin film deposition was performed in argon atmosphere with pressure around 10-2 to 10-4 Torr, RF power between 100-250 W and temperature from room temperature up to 250°C. X-ray diffraction indicates that the thin films are amorphous. Deposition rate and sulphur concentration showed a clear dependence on variation in RF power. Surface roughness increase as temperature was increased from room temperature up to 250°C. Photocurrent increases about 20% under white light illumination. The thin films are continuous with low roughness which might make it a potential candidate for wafer-scale production for advanced electronics or sensor applications.

• Hansen, Per-Anders; Fjellvåg, Helmer; Finstad, Terje & Nilsen, Ola (2016). Luminescence properties of lanthanide and ytterbium lanthanide titanate thin films grown by atomic layer deposition. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films.  ISSN 0734-2101.  34:01A130 . doi: 10.1116/1.4936389
• Hu, Yang; Ruud, Amund; Miikkulainen, Ville; Norby, Truls; Nilsen, Ola & Fjellvåg, Helmer (2016). Electrical characterization of amorphous LiAlO2 thin films deposited by atomic layer deposition. RSC Advances.  ISSN 2046-2069.  6(65), s 60479- 60486 . doi: 10.1039/c6ra03137d
• Lanford, WA; Parenti, M; Nordell, BJ; Paquette, MM; Caruso, AN; Mäntymäki, M; Hämäläinen, J.; Ritala, M; Klepper, Karina Barnholt; Miikkulainen, Ville; Nilsen, Ola; Tenhaeff, W; Dudney, N; Koh, D; Banerjee, SK; Mays, E; Bielefeld, J & King, SW (2016). Nuclear reaction analysis for H, Li, Be, B, C, N, O and F with an RBS check. Nuclear Instruments and Methods in Physics Reseach B.  ISSN 0168-583X.  371, s 211- 215 . doi: 10.1016/j.nimb.2015.10.052
• Lausund, Kristian Blindheim & Nilsen, Ola (2016). All-gas-phase synthesis of UiO-66 through modulated atomic layer deposition. Nature Communications.  ISSN 2041-1723.  7 . doi: 10.1038/ncomms13578
• Müller, Benjamin; Haugen, Håvard Jostein; Nilsen, Ola & Tiainen, Hanna (2016). Atomic layer deposited TiO2 protects porous ceramic foams from grain boundary corrosion. Corrosion Science.  ISSN 0010-938X.  106, s 35- 42 . doi: 10.1016/j.corsci.2016.01.023 Vis sammendrag

  Intergranular corrosion causes a significant loss of compressive strength in highly porous TiO2 foams. In this study, the resistance of conformal atomic layer deposited (ALD) coatings against intergranular corrosion has been investigated. ALD coated TiO2 foams maintained 107% ± 20% and 94% ± 10% of their initial compressive strength for films deposited at 150 °C and 250 °C, respectively. After an immersion period of 28 days in 1 mM HCl, amorphous films showed greater potential in corrosion protection of polycrystalline TiO2 foams. However, anatase coatings with sufficient protection may be more beneficial for cell-material interactions.

• Rauwel, Erwan Yann; Galeckas, Augustinas; Rauwel, Protima; Hansen, Per-Anders; Wragg, David; Nilsen, Ola & Fjellvåg, Helmer (2016). Metal oxide nanoparticles embedded in rare-earth matrix for low temperature thermal imaging applications. Materials Research Express.  ISSN 2053-1591.  3(5) . doi: 10.1088/2053-1591/3/5/055010
• Samarasingha, Pushpaka; Andersen, Niels Højmark; Sørby, Magnus Helgerud; Kumar, Susmit; Nilsen, Ola & Fjellvåg, Helmer (2016). Neutron diffraction and Raman analysis of LiMn1.5Ni0.5O4 spinel type oxides for use as lithium ion battery cathode and their capacity enhancements. Solid State Ionics.  ISSN 0167-2738.  284, s 28- 36 . doi: 10.1016/j.ssi.2015.11.018
• Sønsteby, Henrik; Nilsen, Ola & Fjellvåg, Helmer (2016). Atomic layer deposition of (K,Na)(Nb,Ta)O3 thin films. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films.  ISSN 0734-2101.  34(4) . doi: 10.1116/1.4953406

Se alle arbeider i Cristin

• Fjellvåg, Øystein; Sønsteby, Henrik Hovde; Nilsen, Ola; Wolff, Max; Kapaklis, Vassilios; Fjellvåg, Helmer; Frommen, Christoph & Hauback, Bjørn (2020). Towards Multiferroic Thin Film Composites by Atomic Layer Deposition (ALD).
• Killi, Veronica Anne-Line Kathrine; Nilsen, Ola & Sønsteby, Henrik Hovde (2020). Tynne filmer av ruthenater med atomlagsdeposisjon (ALD).
• Sørensen, Silje Holm; Nilsen, Ola & Hansen, Per-Anders Stensby (2020). Organic Sensitization in Lanthanide Fluoride Nanostructures for Upconversion. Vis sammendrag

  The objective of this thesis is to make organic sensitized upconversion thin films for application on photovoltaic and photocatalytic devices. Upconversion is a light conversion process where two photons of low energy come together to form one photon of higher energy. Using this technique, the light from the sun can be modified to correlate with the bandgaps of for example solar cells. This could potentially increase the efficiencies of the devices drastically. To ensure an efficient upconversion process, organic dyes can be implemented into the system. Organic dyes are good absorbers and can therefore work as sensitizers, increasing the efficiencies of the upconversion process. We have explored how molecular layer deposition (MLD) can be used to synthesize thin films of such upconversion structures. The work in this project has been twofold with one part focusing on implementation of organic dyes into thin films using MLD and the second part aiming to make an upconversion system. During the first part of the project, we proved that the sublimation temperatures of perylenes, a group of large organic dyes are highly dependent on their intramolecular forces. We identified that the perylene FA5 with a molecular mass of 985.12 g/mol still is suitable as a precursor for MLD growth despite its large molecular mass. This is a significant expansion in use of heavy molecules for MLD, as compared to prior experience. Furthermore, perylenes have successfully been implemented into thin films using β-diketonates Ln(thd)3as cation precursors. The perylene based films have been made both with and without using the amino acid glycine as a linker between the Ln and the perylene. The films containing glycine have remarkably higher growth ratesthan thosewithout, due to formation of a Ln-Glycine phase during growth. The growth dynamics have been explored by quartz crystal microbalance (QCM) and the optical properties by UV-Vis, showing stronger absorbing properties in the films deposited without linker.All perylene based films formed structuresclose to the stoichiometryLn2Perylene3. The upconversion properties were explored through depositions of lanthanide-fluoride thin films with Tm3+and Nd3+doped in an YbF3matrix. Both dopants were successfully implemented as both Tm3+and Nd3+ luminescence can be seen from cathodoluminescence (CL) measurements,indicating promising luminescent properties. Growth of YbF3 was explored using NH4F as the chosen fluoride precursor and Yb(thd)3 as Yb precursor. We obtained growth rates of approximately 0.2 Å/cycle with good reproducibility, making it a good system.

• Bratvold, Jon E.; Nilsen, Ola & Fjellvåg, Helmer (2019). Towards a Model System for Lamellar Magnetism by Atomic Layer Deposition. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 2093.
• Brennhagen, Anders; Kvamme, Kristian Breivik; Sverdlilje, Katja S. S. & Nilsen, Ola (2019). Amorphous Iron Phosphates for Thin Film batteries.
• Brennhagen, Anders & Nilsen, Ola (2019). Forskningstorget 2019 - Batteriproduksjon på stand.
• Brennhagen, Anders; Nilsen, Ola; Kvamme, Kristian Breivik & Sverdlilje, Katja S. S. (2019). Synthesis and electrochemical characterization of thin film iron phosphates as cathode material for Li-ion batteries. Vis sammendrag

  Solid-state batteries is one of the main contenders for domination of the future battery marked. Thin film technology is important in the development of these batteries. In this work, we have shown that amorphous thin film FePO4 with a thickness around 10 nm, deposited by atomic layer deposition (ALD), can reach a specific power above 1 MW/kg and approach theoretical capacity at lower currents. The 10 nm thin film also shows very good cycling stability at elevated currents and can retain 70 % of peak capacity after 8000 cycles at 80 µA (40C). The material also shows a significant self-enhancing mechanism leading to an increase in capacity during early cycling stages. We observed a capacity increase of 90 % for 10 nm after 100 cycles at 80 µA. In this study, we used quartz crystal microbalance (QCM) analysis to establish a stable ALD process for depositing amorphous thin films from the Fe-P-O system. By varying the pulsing ratio between the precursors, we obtained films with different compositions and chose to study Fe4(P2O7)3 and FePO4 more in detail. The films were uniform and flat with an RMS roughness below 1 nm. As the FePO4 films proved to be significantly better than the Fe4(P2O7)3, we focused mainly on FePO4. We used galvanostatic cycling (GC), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to characterize the electrochemical properties of the thin films. An important part of this study was to develop a good baseline for testing, including the use of reference batteries. In this work, we confirmed that LiClO4 is a better choice than LiPF6 as electrolyte for testing thin film cathodes, because of minimal side reactions with the steel casing. The FePO4 thin films show a combination of capacitive and redox behavior where both contribute to the capacity. In this study, we have tried to separate the two contributions and find their thickness and current dependency. In an attempt to increase the area capacity of the cathodes without increasing the film thickness, we created soot substrates with high surface 3D structures of carbon, deposited from the flames of a candle. We managed to maintain the structure and evenly coat it with FePO4. Despite the increase in mass, we obtained no higher capacity or better battery performance from the soot batteries.

• Chavan, Sachin Maruti; Gorzkowska-Sobas, Agnieszka A; de Koning, Martijn; Lausund, Kristian Blindheim; Petrovic, Veljko & Nilsen, Ola (2019). Towards adsorptive and catalytically active materials using an all-gas-phase UiO-66-NH2 synthesis approach.
• de Koning, Martijn; Gorzkowska-Sobas, Agnieszka A; Lausund, Kristian Blindheim; Petrovic, Veljko; Nilsen, Ola & Smith, Martin W. (2019). Thin layers of UiO-66-NH2 and their catalytic activity towards selected chemical warfare agents.
• Dziadkowiec, Joanna; Zareeipolgardani, Bahareh; Bratvold, Jon E.; Nilsen, Ola; Dysthe, Dag Kristian & Røyne, Anja (2019). Long-range repulsive forces between reactive calcite surfaces are generated due to nucleation in a confined solution.
• Gorzkowska-Sobas, Agnieszka A; Lausund, Kristian Blindheim; Petrovic, Veljko; de Koning, Martijn; Chavan, Sachin Maruti; Smith, Martin W. & Nilsen, Ola (2019). Ammonia adsorption in metal-organic framework materials MLD-deposited on functional substrate for respiratory protection purposes.
• Hval, Halvor Høen; Ruud, Amund; Forseth, Sissel; Emerich, Hermann; Nilsen, Ola & Fjellvåg, Helmer (2019). Operando investigation of batteries.
• Hval, Halvor Høen; Tripathi, Alok Mani; Ruud, Amund; Emerich, Hermann; Forseth, Sissel; Nilsen, Ola & Fjellvåg, Helmer (2019). Make Batteries Safe Again.
• Hval, Halvor Høen; Tripathi, Alok Mani; Ruud, Amund; Emerich, Hermann; Forseth, Sissel; Nilsen, Ola & Fjellvåg, Helmer (2019). Make Batteries Safe Again.
• Koposov, Alexey; Gandrud, Knut Bjarne; Lai, Samson Yuxiu; Jensen, Ingvild Julie Thue; Nagell, Marius Uv; Nilsen, Ola & Mæhlen, Jan Petter (2019). Silicon on the Road. Vis sammendrag

  IFE together with the UiO, University of Tours (France) and SINTEF recently started a new project “Silicon-on-the-Road”, with the primary aim to develop new silicon-based anode materials for lithium ion batteries. Stabilizing the surfaces of silicon particles has proven to be the most challenging step in the development of high capacity silicon-based electrodes. One of the objectives is therefore to create a material that than can coat the active particles and deliver structural integrity for the anode while keeping all the attractive properties of silicon. The project encompasses a range of coating and analyses methodologies. The current presentation will focus on results obtained using one of the more versatile methods; Atomic Layer Deposition (ALD) and our recent results on thin-film electrodes of amorphous Si as model systems for coating development. This project is co-funded by Norwegian industry and the Research Counsil of Norway through the EnergiX program.

• Kvamme, Kristian Breivik; Ruud, Amund; Weibye, Kristian & Nilsen, Ola (2019). Phosphites as precursors in thin film synthesis. Using LiPO as cathode coating in Li-ion batteries.
• Kvamme, Kristian Breivik; Ruud, Amund; Weibye, Kristian & Nilsen, Ola (2019). Phosphites as precursors in thin film synthesis. Using LiPO as cathode coating in Li-ion batteries..
• Nitsche Kvalvik, Julie; Hansen, Per-Anders Stensby & Nilsen, Ola (2019). Area-selective deposition of MoO3 thin films by atomic layer deposition.
• Olsen, Malin Solheim; Nilsen, Ola & Rukke, Håkon Valen (2019). Porphyrin-based films for photodynamic inactivation of bacteria.
• Petrovic, Veljko; Nilsen, Ola & Lausund, Kristian Blindheim (2019). Boronic acids in Molecular Layer Deposition.
• Dziadkowiec, Joanna; Javadi, Shaghayegh; Bratvold, Jon E.; Nilsen, Ola & Røyne, Anja (2018). Adhesive and repulsive forces between calcite surfaces.
• Dziadkowiec, Joanna; Javadi, Shaghayegh; Bratvold, Jon E.; Nilsen, Ola & Røyne, Anja (2018). Nucleation in solution confined between reactive surfaces can generate long-range repulsive forces.
• Granerød, Cecilie Skjold; Prytz, Øystein; Monakhov, Eduard & Nilsen, Ola (2018). Measuring optical properties on the nanoscale: a STEM-EELS study of ZnO. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 2034.
• Hansen, Per-Anders Stensby; Meijerink, Andries & Nilsen, Ola (2018). Strong TiO2 sensitization of Tb3+ by preventing Ti-Tb charge transfer quenching in subnanometer multilayer structures.
• Hansen, Per-Anders Stensby; Nesteng, Hanne; Svendsen, Ole Joachim & Nilsen, Ola (2018). Blue, green and red emitting lanthanide-organic hybrid films excitable with long wavelength UV.
• Hansen, Per-Anders Stensby; Zikmund, Tomas; Yu, Ting; Nitsche Kvalvik, Julie; Aarholt, Thomas; Prytz, Øystein; Meijerink, Andries & Nilsen, Ola (2018). Aromatic-fluoride nanocomposite materials by atomic layer deposition.
• Hval, Halvor Høen; Ruud, Amund; Forseth, Sissel; Emerich, Hermann; Nilsen, Ola & Fjellvåg, Helmer (2018). Operando investigation of batteries.
• Hval, Halvor Høen; Ruud, Amund; Forseth, Sissel; Emerich, Hermann; Nilsen, Ola & Fjellvåg, Helmer (2018). Operando investigation of batteries.
• Javadi, Shaghayegh; Dziadkowiec, Joanna; Røyne, Anja; Bratvold, Jon E.; Nilsen, Ola & Hiorth, Aksel (2018). Synthetic CaCO3 surfaces in aqueous solutions – AFM and Surface Force Apparatus (SFA) measurements.
• Kjeldstad, Torunn; Thøgersen, Annett; Galeckas, Augustinas; Monakhov, Eduard; Stange, Marit Synnøve Sæverud & Nilsen, Ola (2018). Aluminum nanowires in amorphous silicon.
• Kvamme, Kristian Breivik; Sverdlilje, Katja Sofie Støren & Nilsen, Ola (2018). Thin film batteries at UiO. Vis sammendrag

  Batteries are fast becoming the go-to energy storage solution of our future, even for highly demanding applications such as aviation. The growing expectations and demands for our future batteries require radical improvements in both design and construction. Several approaches are being pursued throughout the research community. At UiO, we are exploring solid-state electrolytes to fulfil these demands. Changing from a liquid to a solid electrolyte is a drastic change in battery design, and solid electrolytes will significantly improve the properties of batteries. This will in turn enable new applications and further decouple our civilization from fossil fuels. Most solid materials have low ionic conductivity, but not all. We are exploring solid materials with high ionic conductivity, including combinations of organic and inorganic structures forming a class of hybrid materials. This work is based on our previous, successful work on high-performance FePO4 cathode materials that show quasi-capacitive behaviour.

• Momtazi, Leva; Nilsen, Ola & Eidet, Jon Roger (2018). Design and Growth of Bioactive Materials by Molecular Layer Deposition. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 1964.
• Skottvoll, Frøydis Sved; Nilsen, Ola; Krauss, Stefan; Sullivan, Gareth & Wilson, Steven Ray Haakon (2018). Integrating highly miniaturized LC-MS systems with “Organ on a Chip”; the future of preclinical modelling.
• Thøgersen, Annett; Stange, Marit Synnøve Sæverud; Galeckas, Augustinas; Nilsen, Ola & Monakhov, Eduard (2018). Aluminum nanowires in amorphous silicon.
• Dziadkowiec, Joanna; Javadi, Shaghayegh; Bratvold, Jon E.; Nilsen, Ola & Røyne, Anja (2017). Interactions between reactive CaCO3 surfaces in aqueous solutions -Surface Forces Apparatus measurements.
• Getz, Michael; Nilsen, Ola; Fjellvåg, Helmer & Hansen, Per-Anders Stensby (2017). Design and Growth of Luminescent Thin Films by Atomic Layer Deposition. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 1895.
• Kjeldstad, Torunn; Galeckas, Augustinas; Nilsen, Ola; Azarov, Alexander; Stange, Marit Synnøve Sæverud; Diplas, Spyridon & Thøgersen, Annett (2017). Self-assembly of Al-nanowires in silicon.
• Kvamme, Kristian Breivik; Ruud, Amund; Weibye, Kristian & Nilsen, Ola (2017). LiPO barriers by ALD Surface modification of LiFePO4 cathodes. Vis sammendrag

  Lithium phosphate (Li3PO4) is a promising material as solid state electrolyte. In this work a new route for synthesis of phosphorous based materials using Atomic layer deposition (ALD) is demonstrated. The established phosphate precursor for ALD use has been replaced by the more volatile phosphite precursors for synthesis of LiPO and AlPO materials. Furthermore, the LiPO product has been tested as a barrier material onto LiFePO4 cathodes to improve kinetics and cycling performance. We have shown that there is indeed an improvement at low barrier thicknesses Figure 1. Adding barrier layers in the interphase between the cathode and electrolyte can be seen as a step on towards development and implementation of commercially viable solid state electrolytes. Deposition of barriers for battery materials by ALD is not a new field [1]. Films of; AlPO4, FePO4 [2], Al2O3 [3, 4], TiO2 [5], Li3PO4 [5] and LiPON [6] have all been reported. Our novel approach is application of phosphorous precursors in the +III oxidation state, such as trimethyl phosphite (Me3PO3) and triethyl phosphite (Et3PO3). These precursors can replace trimethyl phosphate (Me3PO4) in established deposition routes for aluminium phosphate (AlPO4) [7] and lithium phosphate (Li3PO4) [8, 9] by ALD. Furthermore, the resulting LixPO3 product can form a barrier layer where certain thicknesses will give a positive contribution to kinetics, capacity retention and cycling performance.

• Lausund, Kristian Blindheim & Nilsen, Ola (2017). Crystallization of hybrid films to form the metal-organic framework UiO-66.
• Nilsen, Ola; Gandrud, Knut Bjarne; Ruud, Amund & Fjellvåg, Helmer (2017). Atomic Layer Deposition for Thin-Film Lithium-Ion Batteries, In Julien Bachmann (ed.),  Atomic Layer Deposition in Energy Conversion Applications.  Wiley-VCH Verlagsgesellschaft.  ISBN 9783527339129.  Chapter 6.  s 183 - 207
• Ruud, Amund; Sottmann, Jonas; Slawinski, Wojciech Andrzej; Nilsen, Ola & Fjellvåg, Helmer (2017). Lithiation processes in α-MoO3 for lithium ion battery.
• Sønsteby, Henrik; Fjellvåg, Helmer & Nilsen, Ola (2017). Piezo- and Ferroelectric A+B5+O3 Thin Films.
• Thøgersen, Annett; Kjeldstad, Torunn; Jensen, Ingvild Julie Thue; Muntingh, Agnar Georg Peder; Stange, Marit Synnøve Sæverud; Ulyashin, Alexander; Galeckas, Augustinas; Nilsen, Ola & Monakhov, Edouard (2017). Plasmonic properties of aluminium nanowires in amorphous silicon and inverted silicon nanowires.
• Thøgersen, Annett; Kjeldstad, Torunn; Jensen, Ingvild Julie Thue; Stange, Marit Synnøve Sæverud; Ulyashin, Alexander; Galeckas, Augustinas; Nilsen, Ola; Monakhov, Edouard & Diplas, Spyridon (2017). Growing and characterizing self-organizing aluminium nanowires in amorphous silicon.
• Kjeldstad, Torunn; Galeckas, Augustinas; Monakhov, Edouard; Nilsen, Ola & Thøgersen, Annett (2016). Controllable template approach for ZnO nanowire growth.
• Kjeldstad, Torunn; Galeckas, Augustinas; Nilsen, Ola; Azarov, Alexander; Stange, Marit Synnøve Sæverud; Diplas, Spyridon & Thøgersen, Annett (2016). A new silicon nanostructure.
• Lausund, Kristian Blindheim & Nilsen, Ola (2016). Atomic Layer Deposition of the Metal Organic Framework UiO-66.
• Nilsen, Ola & Sønsteby, Henrik (2016). ALD - From Ideal to Real.
• Røyne, Anja; Bergsaker, Anne Schad; Javadi, Shaghayegh; Dziadkowiec, Joanna; Bratvold, Jon E. & Nilsen, Ola (2016). The role of surface forces and confined fluid films in the slow deformation of rocks.
• Tiainen, Hanna; Müller, Benjamin; Campos, Lluis; Ramis, Joana Maria; Nilsen, Ola & Haugen, Håvard Jostein (2016). Atomic layer deposited TiO2 protects highly porous ceramic bone scaffolds from grain boundary corrosion.
• Tiainen, Hanna; Müller, Benjamin; Campos, Lluis; Ramis, Joana Maria; Nilsen, Ola & Haugen, Håvard Jostein (2016). Atomic layer deposited titanium dioxide layer protects highly porous ceramic foams from grain boundary corrosion.

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