Øystein Prytz

• C. Bazioti, V. S. Olsen, A. Y. Kuznetsov, L. Vines, and Ø. Prytz . Formation of N₂ bubbles along grain boundaries in (ZnO)_1−x(GaN)_x: nanoscale STEM-EELS studies Physical Chemistry Chemical Physics 22, 3779 (2020).
• T. Aarholt, Y. K. Frodason, and Ø. Prytz. Imaging defect complexes in scanning transmission electron microscopy: Impact of depth, structural relaxation, and temperature investigated by simulations Ultramicroscopy 209, 112884 (2020).
• T. Bondevik, H. H. Ness, C. Bazioti, T. Norby, O. M. Løvvik, C. T. Koch, and Ø. Prytz. Investigation of the electrostatic potential of a grain boundary in Y-substituted BaZrO₃ using inline electron holography Physical Chemistry Chemical Physics 21, 17662 (2019).
• C. Bazioti, A. Azarov, K. M. Johansen, B. G. Svensson, L. Vines, A. Y. Kuznetsov, and Ø. Prytz. Role of Nitrogen in Defect Evolution in Zinc Oxide: STEM–EELS Nanoscale Investigations The Journal of Physical Chemistry Letters 10, 4725 (2019).
• C. S. Granerød, B. L. Aarseth, P. D. Nguyen, C. Bazioti, A. Azarov, B. G. Svensson, L. Vines, and Ø. Prytz. Structural and optical properties of individual Zn₂GeO₄ particles embedded in ZnO. Nanotechnology 30, 225702 (2019).
• C. S. Granerød, A. Galeckas, K. M. H. Johansen, L. Vines, and Ø. Prytz. The temperature-dependency of the optical band gap of ZnO measured by electron energy-loss spectroscopy in a scanning transmission electron microscope. Journal of Applied Physics 123, 145111 (2018).
• C. S. Granerød, S. R. Bilden, T. Aarholt, Y. F. Yao, C. C. Yang, D. C. Look, L. Vines, K. M. Johansen, and Ø. Prytz. Direct observation of conduction band plasmons and the related Burstein-Moss shift in highly doped semiconductors: A STEM-EELS study of Ga-doped ZnO. Physical Review B 98, 115301 (2018).
• C. Granerød, W. Zhan, and Ø. Prytz. Automated approaches for band gap mapping in STEM-EELS. Ultramicroscopy 184, 39 (2018).
• W. Zhan, C. S. Granerød, V. Venkatachalapathy, K. M. H. Johansen, I. J. T. Jensen, A. Yu. Kuznetsov, and Ø. Prytz. Nanoscale mapping of optical band gaps using monochromated Electron Energy Loss Spectroscopy. Nanotechnology 28, 105703 (2017).

• Kjeldby, S.B.; Azarov, Alexander; Nguyen, Phuong Dan; Venkatachalapathy, Vishnukanthan; Mikšová, R. & MacKová, A. [Vis alle 9 forfattere av denne artikkelen] (2022). Radiation-induced defect accumulation and annealing in Si-implanted gallium oxide. Journal of Applied Physics. ISSN 0021-8979. 131(12). doi: 10.1063/5.0083858.
• Aarseth, Bjørn Lupton; Granerød, Cecilie Skjold; Galeckas, Augustinas; Azarov, Alexander; Nguyen, Phuong Dan & Prytz, Øystein [Vis alle 7 forfattere av denne artikkelen] (2021). Formation and functionalization of Ge-nanoparticles in ZnO. Nanotechnology. ISSN 0957-4484. 32(50). doi: 10.1088/1361-6528/ac264a. Fulltekst i vitenarkiv
• Song, Xin; Riis, Henrik; Prytz, Øystein & Finstad, Terje (2021). Metallization of ZnSb and contact resistance . Journal of Applied Physics. ISSN 0021-8979. 130(2). doi: 10.1063/5.0043958. Fulltekst i vitenarkiv
• Vasquez, Geraldo Cristian; Bathen, Marianne Etzelmüller; Galeckas, Augustinas; Bazioti, Kalliopi; Johansen, Klaus Magnus H & Maestre, D. [Vis alle 11 forfattere av denne artikkelen] (2020). Strain Modulation of Si Vacancy Emission from SiC Micro- and Nanoparticles. Nano Letters. ISSN 1530-6984. 20(12), s. 8689–8695. doi: 10.1021/acs.nanolett.0c03472. Fulltekst i vitenarkiv
• Hansen, Per-Anders Stensby; Zikmund, Tomas; Yu, Ting; Kvalvik, Julie Nitsche; Aarholt, Thomas & Prytz, Øystein [Vis alle 8 forfattere av denne artikkelen] (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
• Smalc-Koziorοwska, Julita; Moneta, J.; Chatzopoulou, P.; Vasileiadis, I.G.; Bazioti, Kalliopi & Prytz, Øystein [Vis alle 9 forfattere av denne artikkelen] (2020). The heterogeneous nucleation of threading dislocations on partial dislocations in III-nitride epilayers. Scientific Reports. ISSN 2045-2322. 10. doi: 10.1038/s41598-020-74030-y. Fulltekst i vitenarkiv
• Øien-Ødegaard, Sigurd; Bazioti, Kalliopi; Redekop, Evgeniy; Prytz, Øystein; Lillerud, Karl Petter & Olsbye, Unni (2020). A toroidal Zr70 oxysulfate cluster and its diverse packing structures. Angewandte Chemie International Edition. ISSN 1433-7851. 59, s. 21397–21402. doi: 10.1002/anie.202010847. Fulltekst i vitenarkiv
• Gogova-Petrova, Daniela; Olsen, Vegard Skiftestad; Bazioti, Kalliopi; Lee, In-Hwan; Prytz, Øystein & Vines, Lasse [Vis alle 7 forfattere av denne artikkelen] (2020). High electron mobility single-crystalline ZnSnN2 on ZnO (0001) substrates. CrysteEngComm. ISSN 1466-8033. 22(38), s. 6268–6274. doi: 10.1039/d0ce00861c. Fulltekst i vitenarkiv
• Bazioti, Kalliopi; Olsen, Vegard Skiftestad; Kuznetsov, Andrej; Vines, Lasse & Prytz, Øystein (2020). Formation of N2 bubbles along grain boundaries in (ZnO)1−x(GaN)x: nanoscale STEM-EELS studies . Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 22(7), s. 3779–3783. doi: 10.1039/c9cp06025a. Fulltekst i vitenarkiv
• Aarholt, Thomas; Frodason, Ymir Kalmann & Prytz, Øystein (2020). Imaging defect complexes in scanning transmission electron microscopy: Impact of depth, structural relaxation, and temperature investigated by simulations. Ultramicroscopy. ISSN 0304-3991. 209. doi: 10.1016/j.ultramic.2019.112884. Fulltekst i vitenarkiv
• Olsen, Vegard Skiftestad; Baldissera, Gustavo; Zimmermann, Christian; Granerød, Cecilie Skjold; Bazioti, Kalliopi & Galeckas, Augustinas [Vis alle 11 forfattere av denne artikkelen] (2019). Evidence of defect band mechanism responsible for band gap evolution in (ZnO)1−x(GaN)x alloys. Physical review B (PRB). ISSN 2469-9950. 100(16). doi: 10.1103/PhysRevB.100.165201. Fulltekst i vitenarkiv
• Bazioti, Kalliopi; Azarov, Alexander; Johansen, Klaus Magnus H; Svensson, Bengt Gunnar; Vines, Lasse & Kuznetsov, Andrej [Vis alle 7 forfattere av denne artikkelen] (2019). Role of Nitrogen in Defect Evolution in Zinc Oxide: STEM−EELS Nanoscale Investigations. The Journal of Physical Chemistry Letters. ISSN 1948-7185. 10(16), s. 4725–4730. doi: 10.1021/acs.jpclett.9b01472. Fulltekst i vitenarkiv
• Bondevik, Tarjei; Ness, Heine Håland; Bazioti, Kalliopi; Norby, Truls Eivind; Løvvik, Ole Martin & Koch, Christoph T. [Vis alle 7 forfattere av denne artikkelen] (2019). Investigation of the electrostatic potential of a grain boundary in Y-substituted BaZrO3 using inline electron holography. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 21(32), s. 17662–17672. doi: 10.1039/c9cp02676b. Fulltekst i vitenarkiv
• 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
• Birenis, Domas; Ogawa, Yuhei; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro & Prytz, Øystein [Vis alle 7 forfattere av denne artikkelen] (2019). Hydrogen-assisted crack propagation in α-iron during elasto-plastic fracture toughness tests. Materials Science & Engineering: A. ISSN 0921-5093. 756, s. 396–404. doi: 10.1016/j.msea.2019.04.084. Fulltekst i vitenarkiv
• Liu, Xin; Bjørheim, Tor Svendsen; Vines, Lasse; Fjellvåg, Øystein; Granerød, Cecilie Skjold & Prytz, Øystein [Vis alle 10 forfattere av denne artikkelen] (2019). Highly Correlated Hydride Ion Tracer Diffusion in SrTiO3–xHx Oxyhydrides. Journal of the American Chemical Society. ISSN 0002-7863. 141(11), s. 4653–4659. doi: 10.1021/jacs.8b12985. Fulltekst i vitenarkiv
• Olsen, Vegard Skiftestad; Bazioti, Kalliopi; Baldissera, Gustavo; Azarov, Alexander; Prytz, Øystein & Persson, Clas [Vis alle 9 forfattere av denne artikkelen] (2019). Effects of Substrate and Post-Deposition Annealing on Structural and Optical Properties of (ZnO)1-x(GaN)x Films. Physica status solidi (b). ISSN 0370-1972. 256(6). doi: 10.1002/pssb.201800529. Fulltekst i vitenarkiv
• Sky, Thomas Neset; Johansen, Klaus Magnus H; Frodason, Ymir Kalmann; Aarholt, Thomas; Riise, Heine Nygard & Prytz, Øystein [Vis alle 8 forfattere av denne artikkelen] (2019). Diffusion of indium in single crystal zinc oxide: a comparison between group III donors. Semiconductor Science and Technology. ISSN 0268-1242. 34(2), s. 1–6. doi: 10.1088/1361-6641/aafa4c. Fulltekst i vitenarkiv
• Granerød, Cecilie Skjold; Aarseth, Bjørn Lupton; Nguyen, Phuong Dan; Bazioti, Kalliopi; Azarov, Alexander & Svensson, Bengt Gunnar [Vis alle 8 forfattere av denne artikkelen] (2019). Structural and optical properties of individual Zn2GeO4 particles embedded in ZnO. Nanotechnology. ISSN 0957-4484. 30(22), s. 1–6. doi: 10.1088/1361-6528/ab061c. Fulltekst i vitenarkiv
• Zhan, Wei; Kosinskiy, Andrey; Vines, Lasse; Johansen, Klaus Magnus H; Almeida Carvalho, Patricia & Prytz, Øystein (2019). ZnCr2O4 Inclusions in ZnO Matrix Investigated by Probe-Corrected STEM-EELS. Materials. ISSN 1996-1944. 12. doi: 10.3390/ma12060888. Fulltekst i vitenarkiv
• Birenis, Domas; Ogawa, Yuhei; Matsunaga, Hisao; Takakuwa, Osamu; Prytz, Øystein & Yamabe, Junichiro [Vis alle 7 forfattere av denne artikkelen] (2018). Hydrogen-assisted fatigue crack propagation in a commercially pure BCC iron. PVP - American Society of Mechanical Engineers. Pressure Vessels and Piping Division. ISSN 0277-027X. 6B-2018. doi: 10.1115/PVP2018-84783. Fulltekst i vitenarkiv
• Olsen, Vegard Skiftestad; Bazioti, Kalliopi; Azarov, Alexander; Svensson, Bengt Gunnar; Kuznetsov, Andrej & Prytz, Øystein [Vis alle 7 forfattere av denne artikkelen] (2018). Bandgap bowing in crystalline (ZnO)1-x(GaN)x thin films; influence of composition and structural properties. Semiconductor Science and Technology. ISSN 0268-1242. 34, s. 1–7. doi: 10.1088/1361-6641/aaee4a.
• Jensen, Ingvild Julie Thue; Johansen, Klaus Magnus H; Zhan, Wei; Venkatachalapathy, Vishnukanthan; Brillson, Len & Kuznetsov, Andrej [Vis alle 7 forfattere av denne artikkelen] (2018). Bandgap and band edge positions in compositionally graded ZnCdO. Journal of Applied Physics. ISSN 0021-8979. 124(1), s. 015302-1–015302-8. doi: 10.1063/1.5036710. Fulltekst i vitenarkiv
• Granerød, Cecilie Skjold; Bilden, Sindre Rannem; Aarholt, Thomas; Yao, Yu-Feng; Yang, C. C. & Look, David C. [Vis alle 9 forfattere av denne artikkelen] (2018). Direct observation of conduction band plasmons and the related Burstein-Moss shift in highly doped semiconductors: A STEM-EELS study of Ga-doped ZnO. Physical review B (PRB). ISSN 2469-9950. 98(11). doi: 10.1103/PhysRevB.98.115301. Fulltekst i vitenarkiv
• 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.
• Ogawa, Yuhei; Birenis, Domas; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro & Prytz, Øystein [Vis alle 7 forfattere av denne artikkelen] (2018). The role of intergranular fracture on hydrogen-assisted fatigue crack propagation in pure iron at a low stress intensity range. Materials Science & Engineering: A. ISSN 0921-5093. 733, s. 316–328. doi: 10.1016/j.msea.2018.07.014.
• Birenis, Domas; Ogawa, Yuhei; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro & Prytz, Øystein [Vis alle 7 forfattere av denne artikkelen] (2018). Interpretation of hydrogen-assisted fatigue crack propagation in BCC iron based on dislocation structure evolution around the crack wake. Acta Materialia. ISSN 1359-6454. 156, s. 245–253. doi: 10.1016/j.actamat.2018.06.041. Fulltekst i vitenarkiv
• Birenis, Domas; Ogawa, Yuhei; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro & Prytz, Øystein [Vis alle 7 forfattere av denne artikkelen] (2018). Hydrogen-assisted fatigue crack propagation in a pure BCC iron. Part II: Accelerated regime manifested by quasi-cleavage fracture at relatively high stress intensity range values. MATEC Web of Conferences. ISSN 2261-236X. 165. doi: 10.1051/matecconf/201816503010. Fulltekst i vitenarkiv
• Ogawa, Yuhei; Birenis, Domas; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro & Prytz, Øystein [Vis alle 7 forfattere av denne artikkelen] (2018). Hydrogen-assisted fatigue crack propagation in a pure BCC iron. Part I: Intergranular crack propagation at relatively low stress intensities. MATEC Web of Conferences. ISSN 2261-236X. 165. doi: 10.1051/matecconf/201816503011. Fulltekst i vitenarkiv
• Ulvestad, Asbjørn; Andersen, Hanne Flåten; Jensen, Ingvild Julie Thue; Mongstad, Trygve; Mæhlen, Jan Petter & Prytz, Øystein [Vis alle 7 forfattere av denne artikkelen] (2018). Substoichiometric Silicon Nitride – An Anode Material for Li-ion Batteries Promising High Stability and High Capacity. Scientific Reports. ISSN 2045-2322. 8. doi: 10.1038/s41598-018-26769-8. Fulltekst i vitenarkiv
• Granerød, Cecilie Skjold; Galeckas, Augustinas; Johansen, Klaus Magnus H; Vines, Lasse & Prytz, Øystein (2018). The temperature-dependency of the optical band gap of ZnO measured by electron energy-loss spectroscopy in a scanning transmission electron microscope. Journal of Applied Physics. ISSN 0021-8979. 123(14), s. 1–6. doi: 10.1063/1.5023316. Fulltekst i vitenarkiv
• Zhan, Wei; Venkatachalapathy, Vishnukanthan; Aarholt, Thomas; Kuznetsov, Andrej & Prytz, Øystein (2018). Band gap maps beyond the delocalization limit: correlation between optical band gaps and plasmon energies at the nanoscale. Scientific Reports. ISSN 2045-2322. 8(848), s. 1–7. doi: 10.1038/s41598-017-18949-9. Fulltekst i vitenarkiv
• Granerød, Cecilie Skjold; Zhan, Wei & Prytz, Øystein (2018). Automated approaches for band gap mapping in STEM-EELS. Ultramicroscopy. ISSN 0304-3991. 184(A), s. 39–45. doi: 10.1016/j.ultramic.2017.08.006. Fulltekst i vitenarkiv
• Ulvestad, Asbjørn; Andersen, Hanne Flåten; Mæhlen, Jan Petter; Prytz, Øystein & Kirkengen, Martin (2017). Long-term cyclability of substoichiometric silicon nitride thin film anodes for Li-ion batteries. Scientific Reports. ISSN 2045-2322. 7(1). doi: 10.1038/s41598-017-13699-0. Fulltekst i vitenarkiv
• Ogawa, Yuhei; Birenis, Domas; Matsunaga, Hisao; Thøgersen, Annett; Prytz, Øystein & Takakuwa, Osamu [Vis alle 7 forfattere av denne artikkelen] (2017). Multi-scale observation of hydrogen-induced, localized plastic deformation in fatigue-crack propagation in a pure iron. Scripta Materialia. ISSN 1359-6462. 140, s. 13–17. doi: 10.1016/j.scriptamat.2017.06.037. Fulltekst i vitenarkiv
• Zhan, Wei; Granerød, Cecilie Skjold; Venkatachalapathy, Vishnukanthan; Johansen, Klaus Magnus H; Jensen, Ingvild Julie Thue & Kuznetsov, Andrej [Vis alle 7 forfattere av denne artikkelen] (2017). Nanoscale mapping of optical band gaps using monochromated Electron Energy Loss Spectroscopy . Nanotechnology. ISSN 0957-4484. 28(10). doi: 10.1088/1361-6528/aa5962. Fulltekst i vitenarkiv Vis sammendrag

  Using monochromated electron energy loss spectroscopy in a probe-corrected scanning transmission electron microscope we demonstrate band gap mapping in ZnO/ZnCdO thin films with a spatial resolution below 10 nm and spectral precision of 20 meV.

• Kosinskiy, Andrey; Karlsen, Ole Bjørn; Sørby, Magnus Helgerud & Prytz, Øystein (2016). Ternary Phases (Heusler) in the System Ti-Co-Sn. Metallurgical and Materials Transactions E. ISSN 2196-2936. 3(4), s. 329–336. doi: 10.1007/s40553-016-0098-5. Fulltekst i vitenarkiv

Se alle arbeider i Cristin

• Bazioti, Kalliopi; Kneiβ, Max; Wenckstern, Holger von; Hage, Fredrik Sydow & Prytz, Øystein (2022). Band Gap Measurements by VEELS of novel κ-(Al0.2Ga0.8)2O3/ κ-(In0.25Ga0.75)2O3 superlattices .
• Bazioti, Kalliopi; Olsen, Vegard Skiftestad; Azarov, Alexander; Johansen, Klaus Magnus H; Kuznetsov, Andrej & Vines, Lasse [Vis alle 7 forfattere av denne artikkelen] (2021). Thermal evolution of point and extended defects in N-implanted ZnO and (ZnO)1−x(GaN)x thin films: STEM-EELS investigations.
• Aarholt, Thomas; Both, Kevin Gregor; Reinertsen, Vilde Mari & Prytz, Øystein (2021). Surface plasmon investigations by STEM-EELS mapping of Au/Ni nanoparticles on STO. Vis sammendrag

  Metallic nanoparticles have traditionally had sharp absorption peaks between 1 and 5 eV due to the excitation of surface plasmons. Localized surface plasmon resonance (LSPR) is the coherent oscillation of quasi-free electrons excited by the electromagnetic fields of a photon or fast electron1,2. Since the absorption peak energies are in the range of visible light, surface plasmons present a potential pathway for absorbing energy to drive photoelectrochemical reactions or contribute to photovoltaic applications. For driving photoelectrochemical reactions, one difficulty is placing photoactive nanoparticles near the catalyst responsible for a chosen reaction, for example, water splitting. The ideal semiconductor for water splitting has a bandgap of 1.9 – 2.3 eV, although semiconductors in this range are seldom stable during photocatalytic water splitting3. Utilizing plasmonics in wide bandgap semiconductors is a promising alternative, avoiding the stability issue3. In this work, we present a STEM-EELS study of Au nanoparticles created by galvanic replacement of Ni nanoparticles grown by exsolution of a PLD-deposited thin-film of A-site excess strontium titanate (Sr1.07Ti 0.93Ni0.07O 3-δ) (STO). STO is an indirect, wide bandgap (3.2 eV) perovskite, studied as a promising photocatalyst for water splitting 4. Ni can easily substitute the Ti in the STO, making it a suitable candidate for exsolution, while Au cannot substitute Ti5. Simultaneously, Ni nanoparticles barely show any plasmonic activities, while Au particles are second only to Ag nanoparticles6. The presented manufacturing technique results in nanoparticles of gold and nickel freestanding, but socketed, on the surface and embedded in the bulk, with diameters between 50 and 100 nm, which are well-suited for plasmonic applications. As a starting point, STEM-EELS was performed with a monochromated 300kV STEM probe with ZeroLoss Peak (ZLP) full-width at half-maximum of 110 meV on an FEI Titan G2. A peculiarly shaped gold nanocluster was studied. After removing the ZLP, the spectrum image was linearly fitted with Gaussians centered at 1.46, 1.95, and 2.40 eV. The 2.40 eV peak is a well-known Au surface plasmon, whereas the remaining two are investigated in conjunction with modeling approaches. An RGB composite of the fit results can be seen in figure 1. Spectra extracted from the coloured regions can be seen in figure 2.

• Kjeldby, Snorre Braathen; Azarov, Alexander; Aarholt, Thomas; Prytz, Øystein & Vines, Lasse (2021). Defect-annealing in Si+-implanted β-Ga2O3.
• Kjeldby, Snorre Braathen; Nguyen, Phuong Dan; Haug, Kristian; Galeckas, Augustinas; Jensen, Ingvild Julie Thue & Thøgersen, Annett [Vis alle 8 forfattere av denne artikkelen] (2021). EELS and SEM-CL investigations of ZnFe2O4 nanoparticles and iron-decorated inversion domain boundaries in bulk ZnO.
• Elgvin, Cana; Nguyen, Phuong Dan; Both, Kevin Gregor; Vines, Lasse & Prytz, Øystein (2021). Crystallographically oriented ZnFe2O4 nanoparticles in ZnO thin films .
• Bazioti, Kalliopi; Olsen, Vegard Skiftestad; Azarov, Alexander; Johansen, Klaus Magnus H; Svensson, Bengt Gunnar & Kuznetsov, Andrej [Vis alle 8 forfattere av denne artikkelen] (2020). Role of nitrogren in defect evolution in ZnO and (ZnO)₁−ₓ(GaN)ₓ: STEM-EELS nanoscale investigations.
• Thøgersen, Annett; Diplas, Spyridon; Michel, Kathrin; Bjørheim, Tor Svendsen; Prytz, Øystein & Norby, Truls Eivind (2020). The surface of CeO2 unravelled.
• Bondevik, Tarjei; Prytz, Øystein & Norby, Truls Eivind (2019). Investigation of the electrostatic potential of a grain boundary in Y-substituted BaZrO3 using inline electron holography.
• Song, Xin; Riis, Henrik; Prytz, Øystein & Finstad, Terje (2019). Metallization of selected transition metals on ZnSb by electron beam thermal evaporation. Vis sammendrag

  The thermoelectric module made by ZnSb can be dated back to 1870, even if the performance was considerable low by today’s standard [1]. In recent decades, both the electrical properties and thermal properties of the material have been improved, attributed to introducing proper doping/co-doping and nanostructuring [2]. The figure of merit of ZnSb has been reported close to 1 or even above in a few studies [3], which is considered to be a material with a possible decent thermoelectric performance. In this study, we focus on the electrical contact resistance between ZnSb and metal contact, i.e the metallization of ZnSb. This is a step forward from optimized thermoelectric material to a useful thermoelectric device. For thermoelectric devices, ohmic contact is mostly wanted. In theory, ohmic contacts are derived from Schottly contacts and is dependent on the work function between semiconductor and metal, and doping concentration; while in reality, many other factors can have significant impacts on function and performance, for instance interface defects, adhesion, thermal expansion between semiconductor and metal, inter-diffusion and oxidation. The scope of this work is to test the method for metallization and understand the transport at the contact. In addition, we verified the methodology for measuring contact resistance and estimated the experimental uncertainties. We selected several transition metals that are often used as electrical contact for semiconductor devices. The substrates, i.e. ZnSb with various doping concentration, have been synthesized by the hot-pressing method and prepared by the standard procedure for wafer preparation. We deposited the metal with electron beam thermal evaporation, following post-annealing at different temperatures. The structure at interface was investigated by Transmission Electron Microscopy (TEM). The contact resistance and semiconductor resistivity were extrapolated from transmission line measurements of samples subjected to different post-annealing. We compared the measurements with the idealized models combining thermionic emission, thermionic filed emission and tunneling. Although this model is an idealization, it can provide a guide for further detailed study.

• Bazioti, Kalliopi; Olsen, Vegard Skiftestad; Azarov, Alexander; Kuznetsov, Andrej; Vines, Lasse & Prytz, Øystein (2019). Defect formation and thermal evolution in ZnO-based structures (Highlight talk).
• Vasquez, Geraldo Cristian; Bazioti, Kalliopi; Galeckas, Augustinas; Johansen, Klaus Magnus H; Granerød, Cecilie Skjold & Nguyen, Phuong Dan [Vis alle 8 forfattere av denne artikkelen] (2019). Luminescent properties of Zn2GeO4 nanoparticles embedded in ZnO.
• Haug, Kristian; Nguyen, Phuong Dan; Karlsen, Ole Bjørn; Aarholt, Thomas; Bazioti, Kalliopi & Prytz, Øystein (2019). Zinc ferrite spinel embedded in ZnO matrix for solar applications.
• Nguyen, Phuong Dan; Granerød, Cecilie Skjold; Aarseth, Bjørn Lupton; Bazioti, Kalliopi; Azarov, Alexander & Svensson, Bengt Gunnar [Vis alle 8 forfattere av denne artikkelen] (2019). Structural and optical properties of individual Zn2GeO4 particles embedded in ZnO.
• Aarholt, Thomas; Frodason, Ymir Kalmann & Prytz, Øystein (2019). The impact of local relaxation on defect-complex STEM contrast.
• Bazioti, Kalliopi; Olsen, Vegard Skiftestad; Johansen, Klaus Magnus H; Azarov, Alexander; Kuznetsov, Andrej & Vines, Lasse [Vis alle 7 forfattere av denne artikkelen] (2019). Transmission Electron Microscopy methods for atomic-scale investigations of semiconductor properties .
• Bazioti, Kalliopi; Olsen, Vegard Skiftestad; Alexander, Azarov; Kuznetsov, Andrej; Vines, Lasse & Prytz, Øystein (2019). STEM-EELS investigation of defect formation and thermal evolution in ZnO.
• Ulvestad, Asbjørn; Koposov, Alexey; Skare, Marte Orderud; Preston, Thomas; Prytz, Øystein & Mæhlen, Jan Petter [Vis alle 7 forfattere av denne artikkelen] (2019). Amorphous Silicon Nitride-an Anode Material for the Next Generation Li-Ion Batteries.
• Hansen, Per-Anders Stensby; Zikmund, Tomas; Yu, Ting; Nitsche Kvalvik, Julie; Aarholt, Thomas & Prytz, Øystein [Vis alle 8 forfattere av denne artikkelen] (2018). Aromatic-fluoride nanocomposite materials by atomic layer deposition.
• Finstad, Terje; Song, Xin; Riis, Henrik & Prytz, Øystein (2018). Cu Films on Thermoelectric ZnSb. Vis sammendrag

  ZnSb is a semiconductor that is experiencing a renewed interest as a thermoelectric material (as well for other applications). For thermoelectric applications the high abundance of the elements and their low toxicity are favorable. Most of the reports have been on optimizing the material without explicitly addressing the integration into a thermoelectric module. The necessary physical and electrical contacts to the material are important, challenging efficient fabrication, durability, thermal stability, thermal stress etc. The detailed understanding of the thermoelectrical material ZnSb in intimate contacts with metals is lacking. This work is our first step towards studying metal contacts to ZnSb. We start by studying deposited Cu films on ZnSb because Cu may be one of the constituents of a metallization scheme. Some of the reasons for choosing Cu is that its thermal expansion matches that of ZnSb, Cu has low cost and the technology for bonding patterns to insulator substrates like alumina is well established. Further Cu is a p-type dopant for ZnSb yielding optimum thermoelectric characteristics at the solubility limit. The solubility of Cu in ZnSb should thus promote tunneling and low contact resistance. The Cu/ZnSb interface has been investigated after heat treatments in the temperature range 200 to 350°C. The ZnSb samples were made by hot pressing grains of ZnSb. A 100nm thick layer of Cu was e-beam deposited. The samples are characterized by SEM with EDS and several TEM techniques. The TEM specimens were made by Focused Ion Beam. The elemental distributions and phase formation will be presented. The contact resistance of the samples is also under investigation.

• Ulvestad, Asbjørn; Koposov, Alexey; Skare, Marte Orderud; Mæhlen, Jan Petter; Andersen, Hanne Flåten & Prytz, Øystein [Vis alle 7 forfattere av denne artikkelen] (2018). Amorphous Silicon Nitride - A Novel Anode Material for Li-ion Batteries.
• Riis, Henrik; Song, Xin; Prytz, Øystein & Finstad, Terje (2018). Characterization of Cu/ZnSb interfaces.
• Prytz, Øystein; Karlsen, Ole Bjørn; Nguyen, Phuong Dan; Carvalho, Patricia A. & Lundell, Martin Egge (2018). Illustrert vitenskap. [Tidsskrift]. Bilder.
• Bazioti, Kalliopi; Granerød, Cecilie Skjold; Olsen, Vegard Skiftestad; Vines, Lasse; Svensson, Bengt Gunnar & Prytz, Øystein (2018). (ZnO)1-X(GaN)X thin films studied by high-resolution structural and spectroscopic imaging .
• Bazioti, Kalliopi; Azarov, Alexander; Svensson, Bengt Gunnar & Prytz, Øystein (2018). An aberration-corrected (S)TEM study of N-induced defects in ZnO: formation and thermal evolution.
• Bazioti, Kalliopi; Granerød, Cecilie Skjold; Olsen, Vegard Skiftestad; Vines, Lasse; Svensson, Bengt Gunnar & Prytz, Øystein (2018). Structural-chemical characterization and bandgap measurements at the nanoscale of (ZnO)1-X(GaN)X thin films using (S)TEM methods .
• Bazioti, Kalliopi; Azarov, Alexander; Svensson, Bengt Gunnar & Prytz, Øystein (2018). (S)TEM characterization and thermal evolution of ion-induced defects in ZnO.
• Aarholt, Thomas; Sky, Thomas Neset; Nguyen, Phuong Dan & Prytz, Øystein (2018). Low-kV EELS band gapmeasurements on indium monolayer structures in ZnO.
• Olsen, Vegard Skiftestad; Bazioti, Kalliopi; Azarov, Alexander; Granerød, Cecilie Skjold; Svensson, Bengt Gunnar & Kuznetsov, Andrej [Vis alle 8 forfattere av denne artikkelen] (2018). Bandgap bowing in crystalline (ZnO)1-x(GaN)x thin films.
• Zhan, Wei; Granerød, Cecilie Skjold; Venkatachalapathy, Vishnukanthan; Johansen, Klaus Magnus H; Jensen, Ingvild Julie Thue & Kuznetsov, Andrej [Vis alle 7 forfattere av denne artikkelen] (2018). Reply to Comment on 'Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy'. Nanotechnology. ISSN 0957-4484. 29(31). doi: 10.1088/1361-6528/aac3ed.
• Ness, Heine Håland; Bondevik, Tarjei & Prytz, Øystein (2018). Basic principle of electron holography.
• Bazioti, Kalliopi; Granerød, Cecilie Skjold; Olsen, Vegard Skiftestad; Vines, Lasse; Svensson, Bengt Gunnar & Prytz, Øystein (2017). Structural/chemical characterization and bandgap measurements of (ZnO)1-X(GaN)X thin films using (S)TEM methods.
• Bazioti, Kalliopi; Granerød, Cecilie Skjold; Olsen, Vegard Skiftestad; Vines, Lasse; Svensson, Bengt Gunnar & Prytz, Øystein (2017). Structural and chemical characterization of (ZnO)1-X(GaN)X thin films using (S)TEM methods.
• Bazioti, Kalliopi; Granerød, Cecilie Skjold; Olsen, Vegard Skiftestad; Vines, Lasse; Svensson, Bengt Gunnar & Prytz, Øystein (2017). (S)TEM characterization of magnetron sputtered ZnO:GaN alloy thin films.
• Bazioti, Kalliopi; Granerød, Cecilie Skjold; Olsen, Vegard Skiftestad; Vines, Lasse; Svensson, Bengt Gunnar & Prytz, Øystein (2017). Structural characterization and nanoscale bandgap measurements of (ZnO)1-X(GaN)X thin films.
• Granerød, Cecilie Skjold; Johansen, Klaus Magnus H; Vines, Lasse & Prytz, Øystein (2017). The temperature-dependency of the ZnO band gap measured by STEM-EELS.
• Granerød, Cecilie Skjold; Galeckas, Augustinas; Vines, Lasse; Johansen, Klaus Magnus H & Prytz, Øystein (2017). Temperature-dependency of the ZnO band gap measured by STEM-EELS.
• Riis, Henrik; Finstad, Terje & Prytz, Øystein (2017). Metallization of ZnSb.
• Granerød, Cecilie Skjold; Zhan, Wei & Prytz, Øystein (2017). Methods for Mapping the Band Gap with High Spatial Resolution by STEM-EELS.
• Granerød, Cecilie Skjold; Galeckas, Augustinas; Johansen, Klaus Magnus H; Vines, Lasse & Prytz, Øystein (2017). The temperature-dependency of the ZnO bandgap studied by STEM-EELS.
• Elanchcelian, Seyon; Granerød, Cecilie Skjold & Prytz, Øystein (2017). TEM-EELS analysis of bandgap properties in 𝛃-Ga2O3.
• Granerød, Cecilie Skjold; Bilden, Sindre Rannem; Zhan, Wei; Vines, Lasse; Johansen, Klaus Magnus H & Prytz, Øystein (2017). Measuring the ZnO bandgap and its temperature dependency with STEM-EELS.
• Granerød, Cecilie Skjold; Zhan, Wei; Aarseth, Bjørn Brevig; Nguyen, Phuong Dan; Johansen, Klaus Magnus H & Vines, Lasse [Vis alle 7 forfattere av denne artikkelen] (2016). Bandgap measurements by STEM-EELS.
• Granerød, Cecilie Skjold & Prytz, Øystein (2016). Advantages of EELS Measurements.
• Granerød, Cecilie Skjold; Zhan, Wei; Johansen, Klaus Magnus H; Vines, Lasse & Prytz, Øystein (2016). Band gap measurements by STEM EELS.
• Granerød, Cecilie Skjold; Nguyen, Phuong Dan; Gunnæs, Anette Eleonora & Prytz, Øystein (2016). The Structure Physics group.
• Ulvestad, Asbjørn; Andersen, Hanne Flåten; Mæhlen, Jan Petter; Prytz, Øystein & Kirkengen, Martin (2016). Amorphous SiNx Thin Film Anodes for Li-Ion Batteries.
• Ulvestad, Asbjørn; Andersen, Hanne Flåten; Mæhlen, Jan Petter; Prytz, Øystein & Kirkengen, Martin (2016). Amorphous SiNx Thin Film Anodes for Li-Ion Batteries.
• Johansen, Klaus Magnus H; Zhan, Wei; Jensen, Ingvild Julie Thue; Granerød, Cecilie Skjold; Venkatachalapathy, Vishnukanthan & Brillson, Leonard J. [Vis alle 8 forfattere av denne artikkelen] (2016). Mapping of Optical band gaps using Electron Energy Loss Spectroscopy in ZnCdO-alloys.
• Tofan, Raluca; Echevarria-Bonet, Cristina; Berland, Kristian; Schrade, Matthias; Sørby, Magnus Helgerud & Hauback, Bjørn Christian [Vis alle 10 forfattere av denne artikkelen] (2016). The effect of spark plasma sintering on structure and phase stability in half-Heusler thermoelectric alloys.
• Bergli, Jørgen; Prytz, Øystein; Nguyen, Phuong Dan & Karlsen, Ole Bjørn (2021). Solid state precipitation of spinels in zinc oxide - A microstructure study. Universitetet i Oslo, Det matematisk-naturvitenskapelige fakultet. Vis sammendrag

  In this work we have investigated the possibility for solid state precipitation of spinel crystals in zinc oxide by separate addition of three different dopant elements. These dopant elements were iron, antimony and vanadium, and were generally introduced as oxide powders. The dopant compounds were mixed with zinc oxide using a powder synthesis route, where the annealing temperature was mostly kept below the solidus temperature in the given system. Some experiments were also performed using a single crystal of zinc oxide embedded in iron oxide and zinc oxide powders. These samples are referred to as diffusion couples. The characterization of samples was carried out by adopting several observation methods. That is light microscopy, x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy and scanning transmission electron microscopy. This variety of methods enabled complementary information to be obtained. It was found that the zinc oxide – iron system displays the most promising features in regard to precipitating spinels crystals in the zinc oxide matrix. This property is attributed to a highly temperature dependent solid solubility of iron in zinc oxide. Observations made in this system indicate that two different spinel forming mechanisms are possible. One includes a high solute iron concentration in zinc oxide and consequently precipitation during cooling of the sample. In the other route a second annealing step is added to promote the precipitation from a somewhat low iron concentration in the zinc oxide matrix. The physical appearance of the precipitates was different depending on precipitation route, however the same orientation relationship with adjacent zinc oxide grains/matrix was found for both spinel precipitates. In addition, iron rich inversion domain boundaries were seen in the single crystal. These were explored, and it was found that the spacing between the domains matched the iron concentration profile in the same region. The transition from inversion domain boundaries to spinel grains was probed to understand nucleation mechanisms for both features. In the two other systems, antimony and vanadium doped zinc oxide, no precipitations were found. However, it was found that zinc oxide had low and more or less constant solid solubility when temperature was varied in these systems, which is assumed to be a determining factor in limiting the possibility for precipitations. Therefore, attempts were done in the zinc oxide – vanadium system to increase the solubility. However, despite interesting synthesis development, we were not able to increase the solid solubility. In the zinc oxide – antimony system we show that etching of surfaces could be a way to render inversion domain boundaries visible in scanning electron microscopes. We also confirm the volatility of antimony by the use of x-ray diffraction and energy dispersible spectroscopy.

• Bergli, Jørgen & Prytz, Øystein (2021). Solid state precipitation of spinels in zinc oxide - A microstructure study. University of Oslo, Department of Physics.
• Elgvin, Cana & Prytz, Øystein (2021). Characterization and optical properties of ZnFe2O4 nanoparticles in ZnO thin films - A (S)TEM study. University of Oslo, Department of Physics.
• Kiste, Mikael Bergedalen & Prytz, Øystein (2020). Characterization of electrical properties in ZnO and SiC; A study of semiconductor band structure by automating procedures in a Transmission Electron Microscope. Kjemisk Institutt, Universitetet i Oslo.
• Haug, Kristian & Prytz, Øystein (2019). Functionalization of transparent conducting oxides. Zinc ferrite spinel in ZnO. Fysisk institutt, Universitetet i Oslo.
• Granerød, Cecilie Skjold; Prytz, Øystein; Monakhov, Eduard & Nilsen, Ola (2018). Measuring optical properties on the nanoscale: a STEM-EELS study of ZnO. Universitetet i Oslo. ISSN 1501-7710.
• Zhan, Wei; Prytz, Øystein; Kuznetsov, Andrej & Flage-Larsen, Espen (2018). Band gap mapping of alloyed ZnO using probe-corrected and monochromated STEM-EELS. Reprosentralen, University of Oslo. ISSN 1501-7710. Vis sammendrag

  The band gap of semiconducting ZnO can be readily tuned through alloying it with other relevant oxides, such as CdO, consequently extending the performance of the corresponding materials and devices. In this context, one of the challenges is to establish the methodology for two-dimensional band gap measurements on the nanometer scale. Here, monochromated electron energy loss spectroscopy (EELS) in combination with probe-corrected scanning transmission electron microscopy (STEM) can be applied, potentially with much greater success compared to traditional techniques with low spatial resolution. However, up to now, the EELS based band gap mapping technique has not seen widespread use, primarily due to its experimental and data processing complexities. In this work, utilizing state-of-the-art probe-corrected and monochromated STEM-EELS platform without particular instrumental design, we developed and applied methods for acquiring large band gap maps with high spatial resolution. A newly-developed efficient computing method was employed to extract band gap maps from the EELS data after proper background subtraction. All these advances are highlighted by the band gap mapping of Zn1-xCdxO/ZnO hetero structure with a spatial resolution well below 10 nm and a high spectral precision. Nevertheless, band gap measurement by EELS are also restricted in spatial resolution, which is fundamentally determined by the delocalization length (L50) of the inelastic scattering process. The origin of this delocalization is the long range electrostatic interactions between the atomic electrons of the sample and the incident high-energy electrons. The EELS plasmon energy map has obviously higher spatial resolution than the band gap map, and its experiment as well as data extraction is also much easier to perform. In order to push the spatial resolving power in EELS band gap analysis further, the relationship between the band gaps and plasmon energies in Zn1-xCdxO was investigated based on the fact that both depend strongly on the unit cell parameter. A robust quantitative correlation was established, providing a simple and straightforward way to calculate the band gap variations just from the easily measured plasmon energy, with improved spatial resolving ability as compared with the conventional EELS approach. In order to further verify the success of the probe-corrected and monochromated STEM-EELS technique, it was put into application to a new system, namely separate ZnCr2O4 nano-inclusions embedded in ZnO matrix. Band gap mapping of ZnCr2O4 nanoparticles in ZnO matrix and their interface was successfully achieved, confirming the validity of this STEM-EELS approach. In addition, probe-corrected STEM enables sub-ångström imaging, from which the realistic structure can be revealed. We employed atomic-resolution images together with geometric phase analysis (GPA) to analyze the structure and strain at ZnCr2O4/ZnO interfaces, which is of critical importance for thin film growth and may affect band gap.

• Ness, Heine Håland; Prytz, Øystein & Bondevik, Tarjei (2018). Inline Electron Holography - Theoretical and experimental aspects. Unipub forlag. Vis sammendrag

  With ever decreasing size of electronics the need study of sub micrometer structures is prominent. The transmission electron microscope (TEM) gives the possibility to study structures at the nano scale. One technique that the TEM enables is inline electron holography, whith this technique, the electrostatic potential of a material can be found. By using a defocus series of electron micrographs, the full electron wavefunction may be recovered by simulating the processes that take place in the TEM. The phase of the electron wavefunction holds information of the potential experienced by the electron wave. In this thesis, we study a state of the art inline electron holography technique, titled Full Resolution Wave Reconstruction (FRWR). A review of the reconstruction algorithm is given, and we have tested the FRWR capabilities to recover the mean inner potential of Cu2O, and the potential profile across a Cu2O/CuO/ZnO heterojunction. In addition the effects of experimental setup such as objective aperture and energy filtering have been investigated. Furthermore, theoretical values of the mean inner potential have been calculated from following two different models, a non-binding atom model and an ionized atom model. The theoretical values for the mean inner potential of Cu2O was found to be 17.29 V for a nonbinding model and 12.78 V for an ionized atom model, whereas the experiential values was estimated to be 15.46 ± 2.18 V. For the Cu2O/CuO interface, the theoretical calculations gave a potential of 3.13 V and 2.34 V for the non-binding and ionic models, respectively. The experimental value was 1.33 ± 0.70 V. The CuO/ZnO transition gave theoretical values of 3.14 V for the non-binding model and 2.34 V for the ionic model, and an experimental value of 2.60 ± 0.84 V.

• Musland, Lars; Flage-Larsen, Espen; Prytz, Øystein & Bergli, Joakim (2018). Charge carrier transport in multilayered structures; thermoelectric applications. Unipub forlag.
• Prytz, Øystein; Flage-Larsen, Espen & Bilden, Sindre Rannem (2018). Simulation of momentum resolved Electron Energy Loss Spectroscopy in the low loss region using model band structures. Unipub forlag. Vis sammendrag

  One of the key limiting factors to progress within nano science is the ability to measure properties on the relevant length scale. The probe size provided by optical measurements is often larger than the individual nanoscale structures, and the resulting measurement is an average over some large volume, thus other methods must be applied. Electron Energy Loss Spectroscopy (EELS) in a Transmission Electron Microscope (TEM) provides a probe size suitable for measuring on nanoscopic structures, but the physics of the probe change when using electrons instead of photons. The fast electrons passing through the sample carry a significant momentum in addition to energy, and both can be transferred to an electron in the sample. The possible transfer of momentum in addition to energy increases the number of possible excitations immensely thus making the spectra of EELS more complex than its optical equivalent. The EELS-spectra also provide useful information about properties earlier methods could not measure such as excitations resolved by momentum, and a straight measure of transitions across indirect band gaps. However, simulations are key in interpretation of EELS where transitions with momentum transfer contribute. Most simulation software for EELS focus on the optical limit and a production ready software for momentum resolved simulations is so far missing. In the present project a simulation software for EELS is developed for a momentum and energy resolved spectrum. Based on existing theory, a full framework for EELS simulation is developed in the dielectric formulation, strongly depending on the dielectric permittivity. The framework has been implemented with focus on a interactive visualization and interpretation of the result which should be easy to handle. Some limitations have been encountered when it comes to computational cost when mapping both momentum and energy. To limit the computational cost, the permittivity was heavily simplified by treating only its longitudinal component. When applying the software on parabolic bands it was found that the calculated joint density of states reproduced analytically derived results. In calculations of joint density of states of parabolic bands with indirect band gap it was found that the intensity onset had different shape when probing a range of momentum transfers opposed to single momentum transfers. When applied to electronic structure models from tight binding calculations, it was found that the longitudinal permittivity was not sufficient to describe the full response of the systems. The longitudinal permittivity is found insufficient in the presence of transverse electric fields and in non-isotropic systems, thus a correction to the permittivity has been presented, this has not been implemented. To conclude, the developed software indicates that momentum resolved calculations can provide useful information in its simplest manner, and be comparable to experiment with further development.

• Salim Asbah, Richard; Flage-Larsen, Espen & Prytz, Øystein (2018). Quadratic integration over the three dimensional Brillouin zone. Unipub forlag.
• Elanchcelian, Seyon; Prytz, Øystein & Granerød, Cecilie Skjold (2017). TEM-EELS analysis of band gap properties in beta-Ga2O3, Universitetet i Oslo.
• Jeu Chiem, Kevin; Prytz, Øystein & Norby, Truls Eivind (2017). Nanoscale measurements of oxidation states in the CaMnO3/LaMnO3 system using Electron Energy Loss Spectroscopy. Universitetet i Oslo.

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