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• Ousdal, Erlend Lemva; Bathen, Marianne Etzelmüller; Medeiros, Helton Goncalves de; Galeckas, Augustinas; Kumar, Piyush & Martins, Maria I.M. [Vis alle 10 forfattere av denne artikkelen] (2026). Control and tuning of color centers in 4H silicon carbide by application of electric field via Schottky diode. Materials Science in Semiconductor Processing. ISSN 1369-8001. 201. doi: 10.1016/j.mssp.2025.110097. Fulltekst i vitenarkiv Vis sammendrag

  The ability to tune and manipulate the energy and intensity of photons emitted from color centers in semiconductors is of great importance for developing point defect quantum emitters as a platform for future quantum technology (QT) applications. One of the promising materials to realize point defect based QT is silicon carbide (SiC), as it combines a plethora of color center candidates with mature material processing and device fabrication. Here we explore the use of a Schottky diode, fabricated on a highly doped n-type 4H-SiC epitaxial layer, to control and modulate defect-related emission under both forward and reverse bias conditions. Zero phonon lines (ZPLs) from three prominent color centers are investigated: V1, V1’ and V2 assigned to the silicon vacancy, B1 and B2 from the carbon antisite-vacancy pair, and PL4 of the divacancy complex. All the studied defect-related emission wavelengths are found to shift in response to applied bias, but with a varying magnitude and direction of the shift. The electric field-induced variations are assigned to Stark effect and current flow within the device. Furthermore, two unknown defect signatures, labeled K1 and K2, are observed in the vicinity (within 2 meV) of the V2 ZPL and exhibit a strong forward bias dependence. A possible origin related to silicon vacancies perturbed by nearby carbon antisites is discussed.

• Ousdal, Erlend Lemva; Ghezellou, Misagh; Ul-Hassan, Jawad; Kuznetsov, Andrej; Vines, Lasse & Bathen, Marianne Etzelmüller (2025). Identification of electrically active defects in 6⁢𝐻-SiC. PHYSICAL REVIEW MATERIALS. 9(12). doi: 10.1103/qzfw-162p. Fulltekst i vitenarkiv Vis sammendrag

  Deep level defects in silicon carbide (SiC) are of great importance for developing both power electronics and quantum technology applications based on SiC material. While the more technologically mature 4⁢𝐻 polytype has been widely explored, electrical identification of deep level defect states in 6⁢𝐻 -SiC has not been completed. This work aims to identify irradiation-induced charge state transition levels arising from intrinsic defects in 6⁢𝐻 -SiC using deep level transient spectroscopy (DLTS) and the formation energy diagram formalism based on density functional theory (DFT) calculations. By comparing experimental results of 6⁢𝐻 -SiC epitaxial layers with measurements of 4⁢𝐻 -SiC material that has been grown under identical conditions, combined with DFT calculations, we assign possible origins for the observed DLTS-signatures.

• Ghezellou, Misagh; Ousdal, Erlend Lemva; Bathen, Marianne Etzelmüller; Vines, Lasse & Ul-Hassan, Jawad (2025). Influence of different hydrocarbons on impurities and minority carrier lifetime in 4H-SiC epitaxial layers. JPhys Materials. 8, s. 1–12. doi: 10.1088/2515-7639/adb7c0. Fulltekst i vitenarkiv Vis sammendrag

  This study explores the influence of different hydrocarbons, methane and propane, on the properties of 4H-SiC epitaxial layers grown by chloride-based chemical vapor deposition. By systematically varying the C/Si and N/C ratios during epitaxial growth, and employing a comprehensive suite of characterization techniques, a better understanding of how growth conditions influence material properties is gained. We show that the n-type dopant incorporation strongly depends on the choice of hydrocarbon especially at lower doping levels. Furthermore, we have observed that methane contributes to a relatively longer carrier lifetime value compared to propane, though a similar lifetime limiting carbon vacancy defect concentration has been observed for both hydrocarbons in as-grown epitaxial layers. Moreover, additional defect levels are also suggested by deep-level transient spectroscopy, potentially related to chlorine complexes, with varying concentrations depending on the choice of hydrocarbon and C/Si ratio. These observations offer insights into the complicated interplay of factors influencing doping, minority carrier lifetime, and defect formation in 4H-SiC epitaxial layers during the epitaxial growth process, and contribute to the optimization of growth parameters depending on the application in question.

• Ousdal, Erlend Lemva; Bathen, Marianne Etzelmüller; Galeckas, Augustinas; Kuznetsov, Andrej & Vines, Lasse (2024). Formation and stability of point defect color centers in 6H silicon carbide. Journal of Applied Physics. ISSN 0021-8979. 135(22). doi: 10.1063/5.0205832. Fulltekst i vitenarkiv Vis sammendrag

  Point defect color centers acting as single-photon emitters are promising for quantum technology applications and have been extensively studied, e.g., in the 4H polytype of silicon carbide (SiC). However, the physics of such color centers in other SiC polytypes is much less explored. Herein, we study the formation and thermal stability of such color centers in 6H-SiC using photoluminescence spectroscopy. The emissions from typical single-photon emitters, such as silicon vacancies, divacancies, and carbon antisite-vacancy pairs in 6H-SiC, were monitored as a function of the proton irradiation fluence and post-irradiation annealing, and compared to that in 4H-SiC. Overall, at the background of similarities between the emission behavior in 4H- and 6H-SiC polytypes, we observed prominent differences; e.g., for the thermal stability of the carbon antisite-vacancy pair, which exhibited maximized emissions upon 300 and 900  *C anneals in 4H- and 6H-SiC, respectively. Moreover, we observed a range of defect emission signatures not previously reported for 6H-SiC in the literature and discussed their potential origin in the context of the thermal stability. For example, among the PL-lines in 6H-SiC, we detected periodically repeatable emission signatures, resembling the so-called L-lines recently reported in 4H-SiC, even though their exact origin has not yet been settled in the literature. Thus, we use color centers comparison in different polytypes to better understand the nature of the single-photon emitters in SiC.

• Pabst, Oliver; Sørebø, Øystein; Andersen, Karoline Sjøen; Ousdal, Erlend Lemva; Bråthen, Sean William & Rehman, Badi Ur [Vis alle 15 forfattere av denne artikkelen] (2021). Storing information electrically in human skin. Journal of Electrical Bioimpedance. 12(1), s. 73–81. doi: 10.2478/joeb-2021-0010. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Human skin has been classified as a non-volatile memristor and it is shown that information can be stored within for at least three minutes. Here we investigate whether it is possible to store information up to 20 minutes. Furthermore, we investigate whether the information can be based on four different states, not just two (binary). We stored the information into the skin of the forehead of the test subjects under three different electrodes, which allows in principle for 64 different combinations (3 electrodes, 4 states) and one can think of numbers on the base of four. For this experiment, we decided on the numbers 123 4 and 302 4 (that correspond to numbers 27 and 50 in the decimal system). Writing of the different states was done by the application of DC voltage pulses that cause electro-osmosis in the sweat ducts (nonlinear electrical measurements). Based on our results, we were not able to distinguish between four different states. However, we can show that binary information storage in human skin is possible for up to 20 minutes.

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• Ousdal, Erlend Lemva (2024). Controlling directionality of emission from quantum emitters in silicon carbide via natural microstructures. Fulltekst i vitenarkiv
• Ousdal, Erlend Lemva; Bathen, Marianne Etzelmüller & Vines, Lasse (2024). Control and tuning of emission from point defects in silicon carbide using an applied electric field. Fulltekst i vitenarkiv
• Ousdal, Erlend Lemva; Bathen, Marianne Etzelmüller & Vines, Lasse (2023). Controlling directionality of emission from quantum defects through microstructures in Silicon Carbide. Fulltekst i vitenarkiv
• Ousdal, Erlend Lemva; Bathen, Marianne Etzelmüller & Vines, Lasse (2023). Optical and electrical characterization of potential single photon emitters in 6H silicon carbide. Fulltekst i vitenarkiv
• Ousdal, Erlend Lemva (2026). Identification, tuning and control of single-photon emitters in silicon carbide for quantum technology. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Silicon carbide has received much attention as a host material for defects with properties that are highly attractive for quantum technology. The potential for room-temperature operation and industry-friendly integration makes silicon carbide a particularly promising platform. To realize a quantum technology platform based on silicon carbide, a detailed understanding of the defects is required, including how to generate them, how to characterize them, and how to control and manipulate them. This thesis investigates multiple defects in silicon carbide through a chronological study that follows their life cycle from material growth to defect generation, using ion irradiation and thermal treatments, before device-related properties are characterized. The work also includes a comparison of equivalent defects across different polytypes of silicon carbide, providing a more general discussion of defects in the material system. Overall, the results contribute to the understanding of defects in silicon carbide, further maturing the material as a platform for quantum technology.

• Ousdal, Erlend Lemva & Monakhov, Eduard (2020). Electrical and optical properties of graphene and graphene oxide: fundamentals and application. Universitetet i Oslo. Fulltekst i vitenarkiv

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