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• Borgersen, Jon; Karsthof, Robert Michael; Rønning, Vegard; Vines, Lasse; Wenckstern, Holger Von & Grundmann, Marius [Show all 8 contributors for this article] (2023). Origin of enhanced conductivity in low dose ion irradiated oxides. AIP Advances. 13(1), p. 015211-1–015211-5. doi: 10.1063/5.0134699. Full text in Research Archive Show summary

  Significant resistivity variations have previously been observed in oxides subjected to relatively low ion irradiation doses, nominally insufficient to generate the amount of bulk defects needed to explain the phenomena. In an effort to unveil the underlying mechanisms, we performed a systematic comparative study of the resistivity evolution in In 2 O 3 -based oxides as a function of low ion doses and ultraviolet (UV) illumination, observing striking correlations. Specifically, we found that irradiation with ∼3 × 10 12  Si/cm 2 and ∼18 h UV exposure result in similar resistivity drops, interpreted in terms of irradiation/illumination assisted desorption of oxygen containing species from the surface. This was further proven by post-irradiation exposure of one of the samples to an oxygen atmosphere partially restoring the resistivity. Combining the present results with literature data, we conclude that the radiation tolerance of In 2 O 3 -based and similar oxides depends on the surface charge modifications, individual defect contributions, and contributions from defect complexes at low, intermediate, and high doses, respectively.

• Ho, Lok-Ping; Younas, Muhammad; Borgersen, Jon; Khan, Rao Tahir Ali; Rezvani, Seyed Javad & Pollastri, Simone [Show all 12 contributors for this article] (2022). Photoluminescence intensity of Cu-doped ZnO modulated via defect occupancy by applying electric bias. Journal of Physics D: Applied Physics. ISSN 0022-3727. 55(31). doi: 10.1088/1361-6463/ac6912. Full text in Research Archive Show summary

  Abstract Discovering multifunctional materials is of paramount importance for advancing the science and technology. Herein, we report on an optical phenomenon modulated by an electrical process that happened at the metal–ZnO:Cu junction, for which the light emission intensity from the photoluminescence is tuned reversibly by applying electric bias to the junction. Importantly, these observations were correlated with the x-ray absorption measurements, detecting prominent flips in Cu + /Cu 2+ oxidation state occupations in ZnO:Cu film as a function of the resistive switching. Moreover, further analysis of the x-ray absorption data revealed an additional prominent correlation—the signals interpreted as the Zn–O bond fingerprints also exhibited the modulations. By considering the whole set of data, we propose a scenario explaining the modulation phenomena.

• Borgersen, Jon; Johansen, Klaus Magnus H; Vines, Lasse; Wenckstern, Holger von; Grundmann, Marius & Kuznetsov, Andrej (2021). Fermi level controlled point defect balance in ion irradiated indium oxide. Journal of Applied Physics. ISSN 0021-8979. 130(8). doi: 10.1063/5.0062135. Full text in Research Archive Show summary

  Fermi level controlled point defect balance is demonstrated in ion irradiated indium oxide (In2O3). Specifically, our observations can be sub-divided into the formation of isolated Frenkel pairs and secondary defects, correlated with an increase and decrease in resistance, respectively. Importantly, by considering the net charge contribution from the most energetically stable Frenkel pair configurations, we explain the data trends for low doses and determine an upper limit for the Fermi level pinning. Moreover, by comparing the corresponding number of generated carriers with the ballistic defect generation rates, we estimate the dynamic annealing efficiency. Further irradiation toward higher doses is consistent with the buildup of secondary defects. As such, the present data may be of practical use in a variety of In2O3 device applications requiring predictions of its radiation tolerance. In a broader perspective, the present methodology may be valuable for benchmarking defect simulation data in semiconductors in general.

• Olsen, Vegard Skiftestad; Øversjøen, Vetle; Gogova-Petrova, Daniela; Pecz, Bela; Galeckas, Augustinas & Borgersen, Jon Arthur [Show all 9 contributors for this article] (2021). ZnSnN2 in Real Space and k-Space: Lattice Constants, Dislocation Density, and Optical Band Gap. Advanced Optical Materials. doi: 10.1002/adom.202100015. Full text in Research Archive
• Borgersen, Jon; Vines, Lasse; Frodason, Ymir Kalmann; Kuznetsov, Andrej; Wenckstern, Holger von & Grundmann, Marius [Show all 9 contributors for this article] (2020). Experimental exploration of the amphoteric defect model by cryogenic ion irradiation of a range of wide band gap oxide materials. Journal of Physics: Condensed Matter. ISSN 0953-8984. 32(50). doi: 10.1088/1361-648X/abac8b. Full text in Research Archive Show summary

  The evolution of electrical resistance as function of defect concentration is examined for the unipolar n-conducting oxides CdO, β-Ga2O3, In2O3, SnO2 and ZnO in order to explore the predictions of the amphoteric defect model. Intrinsic defects are introduced by ion irradiation at cryogenic temperatures, and the resistance is measured in-situ by current–voltage sweeps as a function of irradiation dose. Temperature dependent Hall effect measurements are performed to determine the carrier concentration and mobility of the samples before and after irradiation. After the ultimate irradiation step, the Ga2O3 and SnO2 samples have both turned highly resistive. In contrast, the In2O3 and ZnO samples are ultimately found to be less resistive than prior to irradiation, however, they both show an increased resistance at intermediate doses. Based on thermodynamic defect charge state transitions computed by hybrid density functional theory, a model expanding on the current amphoteric defect model is proposed.

• Kvalvik, Julie Nitsche; Borgersen, Jon; Hansen, Per-Anders Stensby & Nilsen, Ola (2020). Area-selective atomic layer deposition of molybdenum oxide. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. ISSN 0734-2101. 38(4), p. 042406-1–042406-9. doi: 10.1116/6.0000219. Full text in Research Archive Show summary

  Area-selective bottom-up synthesis routes of thin films are required to overcome the current limits in lithography, and such growth can be achieved with high quality and nanometer thickness control by area-selective atomic layer deposition (AS-ALD). However, the current range of materials demonstrated deposited by AS-ALD is limited, and no processes for molybdenum oxide have been available so far. In this work, the authors explore the properties of a new ALD precursor, MoCl4O, for deposition of molybdenum oxides by ALD. MoCl4O is administered at room temperature during deposition, making it readily available for use. When reacted with a combination of water and ozone, it leads to an AS-ALD process for deposition of MoOx—the first reported. The process is perfectly selective for growth on glass as compared to Si(100) substrates for deposition temperatures between 200 and 300 °C, with a growth rate of 0.72 Å/cycle at 300 °C. The process is attempted on a range of substrates proving good growth on soda-lime glass and LiF and no growth on Si(100), silica, Na2CO3, CaCO3, Li3PO3, or Li2SiO3. The findings of this study indicate an activated process by diffusion of sodium or lithium through the film during growth. The obtained films have further been characterized by x-ray photoelectron spectroscopy, scanning electron microscopy, x-ray diffraction, and atomic force microscopy, revealing films with an RSM roughness of 23 nm with the presence of crystalline MoO2 (C P/m) when deposited at 300 °C and crystalline Mo9O26 when deposited at 250 °C. The rough MoOx thin films may be applicable for electrocatalysis, gas sensors, or lithium-ion batteries. The findings of this study enable AS-ALD synthesis of molybdenum oxide with excellent selectivity not dependent on intermittent etching cycles during growth.

• Gorbitz, Carl Henrik; Paulsen, Jan Christian Holgado & Borgersen, Jon (2015). Redetermined crystal structure of β-DL-methionine at 320 K. Acta Crystallographica Section E: Structure Reports Online. 71(6), p. o398–o399. doi: 10.1107/S2056989015008749. Full text in Research Archive

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• Bathen, Marianne Etzelmüller; Borgersen, Jon Arthur; Karlsen, Kjetil; Nyborg, Martin; Olsen, Vegard Skiftestad & Reinertsen, Vilde Mari [Show all 7 contributors for this article] (2019). Skolebesøk ved MiNaLab. Full text in Research Archive
• Borgersen, Jon; Johansen, Klaus Magnus H; Vines, Lasse; Kuznetsov, Andrej; Frodason, Ymir Kalmann & Wenckstern, Holger von [Show all 9 contributors for this article] (2019). Electrical properties of intrinsic defects in wide band gap oxides. Full text in Research Archive
• Borgersen, Jon; Vines, Lasse; Johansen, Klaus Magnus H; Kuznetsov, Andrej; Wenckstern, Holger von & Perez, Jesus Zuniga [Show all 7 contributors for this article] (2019). Using intrinsic defects as dopants in wide band gap semiconducting oxides. Full text in Research Archive
• Grini, Sigbjørn; Borgersen, Jon Arthur; Sky, Thomas Neset; Frodason, Ymir Kalmann; Riise, Heine Nygard & Zimmermann, Christian (2018). Omvisning MENA. Full text in Research Archive
• Bathen, Marianne Etzelmüller; Borgersen, Jon Arthur; Grini, Sigbjørn; Johansen, Klaus Magnus H; Nyborg, Martin & Olsen, Vegard Skiftestad [Show all 7 contributors for this article] (2017). Omvisning FAM. Full text in Research Archive
• Riise, Heine Nygard; Kjeldstad, Torunn; Sky, Thomas Neset & Borgersen, Jon Arthur (2017). MiNaLab-besøk frå Kongsskogen VGS. Full text in Research Archive
• Riise, Heine Nygard; Bathen, Marianne Etzelmüller; Borgersen, Jon Arthur; Grini, Sigbjørn & Johansen, Klaus Magnus H (2017). Besøk frå Nanoskolen 2017. Full text in Research Archive
• Riise, Heine Nygard; Aarseth, Bjørn Brevig; Kjeldstad, Torunn; Borgersen, Jon Arthur & Olsen, Vegard Skiftestad (2017). Besøk frå deltakarar i Fysikk-OL. Full text in Research Archive
• Bergum, Kristin; Borgersen, Jon Arthur; Ellingsen, Josef Gert Åsheim; Hallén, Anders; Ingebrigtsen, Mads Eide & Kuznetsov, Andrej (2017). Omvisning MiNaLab, Slemdal skole 4. trinn. Full text in Research Archive
• Borgersen, Jon Arthur; Johansen, Klaus Magnus H & Kuznetsov, Andrej (2017). Characterisation of the specific contact resistance to indium oxides. Full text in Research Archive
• Bergum, Kristin; Borgersen, Jon Arthur; Ellingsen, Josef Gert Åsheim; Frodason, Ymir Kalmann; Galeckas, Augustinas & Ingebrigtsen, Mads Eide [Show all 8 contributors for this article] (2017). Omvisning MiNaLab. Full text in Research Archive
• Varslott, Kristoffer Wannebo; Kuznetsov, Andrej; Borgersen, Jon & Bazioti, Calliope (2021). The Effect on Plasmonic Behaviour in Quasi Two-Dimensional GeSe by Variation in Thickness & Phases. Universitetet i Oslo. Full text in Research Archive

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