Øystein Prytz

• Bazioti, Kalliopi; Azarov, Alexander; Johansen, Klaus Magnus H; Svensson, Bengt Gunnar; Vines, Lasse; Kuznetsov, Andrej & Prytz, Øystein (2019). Role of Nitrogen in Defect Evolution in Zinc Oxide: STEM−EELS Nanoscale Investigations. The Journal of Physical Chemistry Letters.  ISSN 1948-7185.  10, s 4725- 4730 . doi: 10.1021/acs.jpclett.9b01472
• Birenis, Domas; Ogawa, Yuhei; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro; Prytz, Øystein & Thøgersen, Annett (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
• Bondevik, Tarjei; Ness, Heine H.; Bazioti, Kalliopi; Norby, Truls Eivind; Løvvik, Ole Martin; Koch, Christoph T. & Prytz, Øystein (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, s 17662- 17672 . doi: 10.1039/c9cp02676b
• Granerød, Cecilie Skjold; Aarseth, Bjørn Lupton; Nguyen, Phuong Dan; Bazioti, Kalliopi; Azarov, Alexander; Svensson, Bengt Gunnar; Vines, Lasse & Prytz, Øystein (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 Full text in Research Archive.
• 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
• Liu, Xin; Bjørheim, Tor Svendsen; Vines, Lasse; Fjellvåg, Øystein; Granerød, Cecilie Skjold; Prytz, Øystein; Yamamoto, Takafumi; Kageyama, Hiroshi; Norby, Truls Eivind & Haugsrud, Reidar (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
• Olsen, Vegard Skiftestad; Baldissera, Gustavo; Zimmermann, Christian; Granerød, Cecilie Skjold; Bazioti, Kalliopi; Galeckas, Augustinas; Svensson, Bengt Gunnar; Kuznetsov, Andrej; Persson, Clas; Prytz, Øystein & Vines, Lasse (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
• Olsen, Vegard Skiftestad; Bazioti, Kalliopi; Baldissera, Gustavo; Azarov, Alexander; Prytz, Øystein; Persson, Clas; Svensson, Bengt Gunnar; Kuznetsov, Andrej & Vines, Lasse (2019). Effects of Substrate and Post-Deposition Annealing on Structural and Optical Properties of (ZnO)1-x(GaN)x Films. Physica status solidi. B, Basic research.  ISSN 0370-1972.  256(6) . doi: 10.1002/pssb.201800529
• Sky, Thomas Neset; Johansen, Klaus Magnus H; Frodason, Ymir Kalmann; Aarholt, Thomas; Riise, Heine Nygard; Prytz, Øystein; Svensson, Bengt Gunnar & Vines, Lasse (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
• 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 Full text in Research Archive.
• Birenis, Domas; Ogawa, Yuhei; Matsunaga, Hisao; Takakuwa, Osamu; Prytz, Øystein; Yamabe, Junichiro & Thøgersen, Annett (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
• Birenis, Domas; Ogawa, Yuhei; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro; Prytz, Øystein & Thøgersen, Annett (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 Full text in Research Archive.
• Birenis, Domas; Ogawa, Yuhei; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro; Prytz, Øystein & Thøgersen, Annett (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
• Granerød, Cecilie Skjold; Bilden, Sindre Rannem; Aarholt, Thomas; Yao, Yu-Feng; Yang, C. C.; Look, David C.; Vines, Lasse; Johansen, Klaus Magnus H & Prytz, Øystein (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 Full text in Research Archive.
• 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 Full text in Research Archive.
• 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 Full text in Research Archive.
• Jensen, Ingvild Julie Thue; Johansen, Klaus Magnus H; Zhan, Wei; Venkatachalapathy, Vishnukanthan; Brillson, Len; Kuznetsov, Andrej & Prytz, Øystein (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 Full text in Research Archive.
• Ogawa, Yuhei; Birenis, Domas; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro; Prytz, Øystein & Thøgersen, Annett (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 Full text in Research Archive.
• Ogawa, Yuhei; Birenis, Domas; Matsunaga, Hisao; Takakuwa, Osamu; Yamabe, Junichiro; Prytz, Øystein & Thøgersen, Annett (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
• Olsen, Vegard Skiftestad; Bazioti, Kalliopi; Azarov, Alexander; Svensson, Bengt Gunnar; Kuznetsov, Andrej; Prytz, Øystein & Vines, Lasse (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
• 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
• Ulvestad, Asbjørn; Andersen, Hanne Flåten; Jensen, Ingvild Julie Thue; Mongstad, Trygve; Mæhlen, Jan Petter; Prytz, Øystein & Kirkengen, Martin (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 Full text in Research Archive.
• 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 Full text in Research Archive.
• Ogawa, Yuhei; Birenis, Domas; Matsunaga, Hisao; Thøgersen, Annett; Prytz, Øystein; Takakuwa, Osamu & Yamabe, Junichiro (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 Full text in Research Archive.
• 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 Full text in Research Archive.
• Zhan, Wei; Granerød, Cecilie Skjold; Venkatachalapathy, Vishnukanthan; Johansen, Klaus Magnus H; Jensen, Ingvild Julie Thue; Kuznetsov, Andrej & Prytz, Øystein (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 Full text in Research Archive. Show summary

  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 Full text in Research Archive.
• Hage, Fredrik Sydow; Kepaptsoglou, Despoina Maria; Seabourne, Ché Royce; Ramasse, Quintim M.; Scott, Andrew J.; Prytz, Øystein; Gunnæs, Anette Eleonora & Helgesen, Geir (2014). Dielectric response of pentagonal defects in multilayer graphene nano-cones. Nanoscale.  ISSN 2040-3364.  6(3), s 1833- 1839 . doi: 10.1039/c3nr05419e
• Hage, Fredrik Sydow; Ramasse, Quentin; Kepaptsoglou, Despoina Maria; Prytz, Øystein; Gunnæs, Anette Eleonora; Helgesen, Geir & Brydson, Rik (2013). Topologically induced confinement of collective modes in multilayer graphene nanocones measured by momentum-resolved STEM-VEELS. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  88(15) . doi: 10.1103/PhysRevB.88.155408
• Prytz, Øystein; Flage-Larsen, Espen; Gu, L.; Sigle, W.; van Aken, Peter A & Taftø, Johan (2012). Charge-ordered spinel AlV2O4: High-energy-resolution EELS and computational studies. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  85(19) . doi: 10.1103/PhysRevB.85.195112

View all works in Cristin

• Aarholt, Thomas; Frodason, Ymir Kalmann & Prytz, Øystein (2019). The impact of local relaxation on defect-complex STEM contrast.
• 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.
• 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).
• Bazioti, Kalliopi; Olsen, Vegard Skiftestad; Johansen, Klaus Magnus H; Azarov, Alexander; Kuznetsov, Andrej; Vines, Lasse & Prytz, Øystein (2019). Transmission Electron Microscopy methods for atomic-scale investigations of semiconductor properties.
• 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.
• 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; Vines, Lasse & Prytz, Øystein (2019). Structural and optical properties of individual Zn2GeO4 particles embedded in ZnO.
• Song, Xin; Riis, Henrik; Prytz, Øystein & Finstad, Terje (2019). Metallization of selected transition metals on ZnSb by electron beam thermal evaporation. Show summary

  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.

• Ulvestad, Asbjørn; Koposov, Alexey; Skare, Marte Orderud; Preston, Thomas; Prytz, Øystein; Mæhlen, Jan Petter & Andersen, Hanne Flåten (2019). Amorphous Silicon Nitride-an Anode Material for the Next Generation Li-Ion Batteries.
• Vasquez, Geraldo Cristian; Bazioti, Kalliopi; Galeckas, Augustinas; Johansen, Klaus Magnus H; Granerød, Cecilie Skjold; Nguyen, Phuong Dan; Prytz, Øystein & Vines, Lasse (2019). Luminescent properties of Zn2GeO4 nanoparticles embedded in ZnO.
• Aarholt, Thomas; Sky, Thomas Neset; Nguyen, Phuong Dan & Prytz, Øystein (2018). Low-kV EELS band gapmeasurements on indium monolayer structures in ZnO.
• Bazioti, Kalliopi; Azarov, Alexander; Svensson, Bengt Gunnar & Prytz, Øystein (2018). (S)TEM characterization and thermal evolution of ion-induced defects in ZnO.
• 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). (ZnO)1-X(GaN)X thin films studied by high-resolution structural and spectroscopic imaging.
• 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.
• Finstad, Terje; Song, Xin; Riis, Henrik & Prytz, Øystein (2018). Cu Films on Thermoelectric ZnSb. Show summary

  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.

• 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; Zikmund, Tomas; Yu, Ting; Nitsche Kvalvik, Julie; Aarholt, Thomas; Prytz, Øystein; Meijerink, Andries & Nilsen, Ola (2018). Aromatic-fluoride nanocomposite materials by atomic layer deposition.
• Musland, Lars; Flage-Larsen, Espen; Prytz, Øystein & Bergli, Joakim (2018). Charge carrier transport in multilayered structures; thermoelectric applications.
• Ness, Heine Håland; Bondevik, Tarjei & Prytz, Øystein (2018). Basic principle of electron holography.
• Ness, Heine Håland; Prytz, Øystein & Bondevik, Tarjei (2018). Inline Electron Holography - Theoretical and experimental aspects. Show summary

  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.

• Olsen, Vegard Skiftestad; Bazioti, Kalliopi; Azarov, Alexander; Granerød, Cecilie Skjold; Svensson, Bengt Gunnar; Kuznetsov, Andrej; Prytz, Øystein & Vines, Lasse (2018). Bandgap bowing in crystalline (ZnO)1-x(GaN)x thin films.
• 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. Show summary

  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.

• Prytz, Øystein; Karlsen, Ole Bjørn; Nguyen, Phuong Dan; Carvalho, Patricia A. & Lundell, Martin Egge (2018, 21. juni). Illustrert vitenskap. [Tidsskrift].  Bilder.
• Riis, Henrik; Song, Xin; Prytz, Øystein & Finstad, Terje (2018). Characterization of Cu/ZnSb interfaces.
• Salim Asbah, Richard; Flage-Larsen, Espen & Prytz, Øystein (2018). Quadratic integration over the three dimensional Brillouin zone.
• Ulvestad, Asbjørn; Koposov, Alexey; Skare, Marte Orderud; Mæhlen, Jan Petter; Andersen, Hanne Flåten; Prytz, Øystein & Kirkengen, Martin (2018). Amorphous Silicon Nitride - A Novel Anode Material for Li-ion Batteries.
• Zhan, Wei; Granerød, Cecilie Skjold; Venkatachalapathy, Vishnukanthan; Johansen, Klaus Magnus H; Jensen, Ingvild Julie Thue; Kuznetsov, Andrej & Prytz, Øystein (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
• Zhan, Wei; Prytz, Øystein; Kuznetsov, Andrej & Flage-Larsen, Espen (2018). Band gap mapping of alloyed ZnO using probe-corrected and monochromated STEM-EELS. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 1501-7710. Show summary

  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.

• 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 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). Structural characterization and nanoscale bandgap measurements of (ZnO)1-X(GaN)X thin films.
• 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.
• Elanchcelian, Seyon; Granerød, Cecilie Skjold & Prytz, Øystein (2017). TEM-EELS analysis of bandgap properties in -Ga2O3.
• Elanchcelian, Seyon; Prytz, Øystein & Granerød, Cecilie Skjold (2017). TEM-EELS analysis of band gap properties in beta-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; Galeckas, Augustinas; Johansen, Klaus Magnus H; Vines, Lasse & Prytz, Øystein (2017). The temperature-dependency of the ZnO bandgap studied 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.
• 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; Zhan, Wei & Prytz, Øystein (2017). Methods for Mapping the Band Gap with High Spatial Resolution by STEM-EELS.
• Jeu Chiem, Kevin; Prytz, Øystein & Norby, Truls Eivind (2017). Nanoscale measurements of oxidation states in the CaMnO3/LaMnO3 system using Electron Energy Loss Spectroscopy..
• Riis, Henrik; Finstad, Terje & Prytz, Øystein (2017). Metallization of ZnSb.
• Granerød, Cecilie Skjold; Nguyen, Phuong Dan; Gunnæs, Anette Eleonora & Prytz, Øystein (2016). The Structure Physics group.
• Granerød, Cecilie Skjold & Prytz, Øystein (2016). Advantages of EELS Measurements.
• Granerød, Cecilie Skjold; Zhan, Wei; Aarseth, Bjørn Brevig; Nguyen, Phuong Dan; Johansen, Klaus Magnus H; Vines, Lasse & Prytz, Øystein (2016). Bandgap measurements by STEM-EELS.
• Granerød, Cecilie Skjold; Zhan, Wei; Johansen, Klaus Magnus H; Vines, Lasse & Prytz, Øystein (2016). Band gap measurements by STEM EELS.
• Johansen, Klaus Magnus H; Zhan, Wei; Jensen, Ingvild Julie Thue; Granerød, Cecilie Skjold; Venkatachalapathy, Vishnukanthan; Brillson, Leonard J.; Kuznetsov, Andrej & Prytz, Øystein (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; Persson, Clas; Prytz, Øystein; Hansen, Vidar & Gunnæs, Anette Eleonora (2016). Microstructural characterization of spark plasma sintered (X,X’)NiSn half‐Heusler alloys.
• Tofan, Raluca; Echevarria-Bonet, Cristina; Berland, Kristian; Schrade, Matthias; Sørby, Magnus Helgerud; Hauback, Bjørn Christian; Persson, Clas; Prytz, Øystein; Hansen, Vidar & Gunnæs, Anette Eleonora (2016). The effect of spark plasma sintering on structure and phase stability in half-Heusler thermoelectric alloys.
• 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.
• Diplas, Spyridon; Walmsley, John; Holmestad, Randi & Prytz, Øystein (2015). An introduction to NORTEM by the NORTEM management group.
• Granerød, Cecilie Skjold; Nguyen, Phuong Dan; Zhan, Wei; Monakhov, Edouard & Prytz, Øystein (2015). Band gap measurements by STEM-EELS.
• Granerød, Cecilie Skjold; Nguyen, Phuong Dan; Zhan, Wei; Monakhov, Edouard & Prytz, Øystein (2015). High Energy Resolution EELS on ZnO/Cu2O Heterostructures.
• Granerød, Cecilie Skjold; Nilsen, Ola; Monakhov, Edouard & Prytz, Øystein (2015). Bandgaps in the TEM.
• Granerød, Cecilie Skjold; Zhan, Wei; Aarseth, Bjørn Brevig; Vines, Lasse & Prytz, Øystein (2015). Band gap measurements by STEM EELS.
• Granerød, Cecilie Skjold; Zhan, Wei; Venkatachalapathy, Vishnukanthan; Kuznetsov, Andrej; Nilsen, Ola; Monakhov, Edouard & Prytz, Øystein (2015). Bandgap of Functional Oxides in STEM-EELS.
• Prytz, Øystein; Zhan, Wei & Granerød, Cecilie Skjold (2015). Status of EELS band gap measurements in the monochromated Titan.
• Ulvestad, Asbjørn; Andersen, Hanne Flåten; Vie, Preben Joakim Svela; Mæhlen, Jan Petter; Prytz, Øystein & Kirkengen, Martin (2015). SiN and SiC Coated Silicon Thin Films as Anodes for Li-Ion Batteries.
• Ulvestad, Asbjørn; Mæhlen, Jan Petter; Andersen, Hanne Flåten; Gunnæs, Anette Eleonora; Prytz, Øystein & Kirkengen, Martin (2015). Characterization of PECVD-Grown a-SiC:H for use as Coating for Silicon Thin Film Anodes in Li-Ion Batteries.
• Ulvestad, Asbjørn; Mæhlen, Jan Petter; Andersen, Hanne Flåten; Xu, Chao; Prytz, Øystein & Kirkengen, Martin (2015). a-SiN:H and a-SiC:H Coated Silicon Thin Films as Anodes for Li-Ion Batteries.
• Wiken Langfeldt, Sindre; Prytz, Øystein; Karlsen, Ole Bjørn & Nguyen, Phuong Dan (2015). Syntese og karakterisering av termoelektriske halv-Heusler materialer av typen (Ti,Zr,Hf)NiSn..
• Zhan, Wei; Kosinskiy, Andrey & Prytz, Øystein (2015). Aberration-corrected High-resolution STEM and EELS on Cr-doped ZnO with Nano ZnCr2O4 Inclusion.
• Zhan, Wei; Venkatachalapathy, Vishnukanthan; Jensen, Ingvild Julie Thue; Granerød, Cecilie Skjold; Flage-Larsen, Espen; Johansen, Klaus Magnus H; Galeckas, Augustinas; Kuznetsov, Andrej & Prytz, Øystein (2015). STEM-EELS Band Gap Measurement in Zn1-XCdXO Thin Films.
• Kosinskiy, Andrey; Prytz, Øystein; Karlsen, Ole Bjørn & Sørby, Magnus Helgerud (2014). X-ray and neutron diffraction study of Co(2-x)TiSn [x < 0.5] solid solution.
• Kosinskiy, Andrey; Prytz, Øystein; Karlsen, Ole Bjørn & Sørby, Magnus Helgerud (2014). yntese- og diffraksjonsstudie av faser i systemene Nb–Fe–Sb og Ti–Co–Sn..
• Løvvik, Ole Martin; Song, Xin; Valset, Kjetil; Flage-Larsen, Espen; Fjeld, Harald; Graff, Joachim Seland; Schrade, Matthias; Karlsen, Ole Bjørn; Larsson, Andreas; Casolo, Simone; Prytz, Øystein; Norby, Truls; Finstad, Terje; Gunnæs, Anette Eleonora & Taftø, Johan (2014). Thermoelectric materials from first principles to final applications: Basic and applied thermoelectrics in Oslo.
• Song, Xin; Persson, Clas; Norby, Truls; Flage-Larsen, Espen; Karlsen, Ole Bjørn; Hansen, Vidar; Gunnæs, Anette Eleonora; Prytz, Øystein; Løvvik, Ole Martin; Finstad, Terje; Valset, Kjetil; Cui, Xuemei; Taftø, Johan; Fjeld, Harald; Hauback, Bjørn & Schrade, Matthias (2014). Conversion of Heat and Energy: Thermoelectrics.
• Holmestad, Randi; Walmsley, John Charles; Prytz, Øystein; Soleim, Bjørn Gunnar; Van Helvoort, Antonius; Olsen, Arne; Gunnæs, Anette Eleonora; Bjørge, Ruben; Sæterli, Ragnhild; Taftø, Johan; Solberg, Jan Ketil; Vullum, Per Erik; Marioara, Calin Daniel; Yu, Yingda; Thørgersen, A.; Rodenwald, M.; Bergius, M. & Lázár, A. (2012). NORTEM – ambitions and plans.
• Løvvik, Ole Martin; Valset, Kjetil; Rauwel, Protima; Prytz, Øystein; Flage-Larsen, Espen; Song, Xin; Karlsen, Ole Bjørn; Bording, Jan Kåre; Hansen, Vidar; Norby, Truls; Finstad, Terje & Taftø, Johan (2012). Thermoelectricity in Oslo.

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