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(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
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. ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
The effects of boron at concentrations ranging from 5 to 525 ppm in low copper spheroidal graphite iron (SGI) has been studied. At 130 to 140 ppm, no particular effect of boron was observed on the size distributions, number ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
Abstract Radiation tolerance is determined as the ability of crystalline materials to withstand the accumulation of the radiation induced disorder. Nevertheless, for sufficiently high fluences, in all by far known ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
Diffusion of Zn in (001)- and (¯201)-oriented β−Ga2O3 was studied using secondary-ion mass spectrometry and first-principles calculations based on hybrid and semilocal functionals. The β−Ga2O3 samples were sealed in quartz ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
In all implantations into crystalline targets, quite a few ions find a path along a crystal channel or plane, so called channeling, and these ions travel deep into the crystal. This paper treats aluminum (Al) implantation ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
Point defects in silicon carbide (SiC) are well positioned for integration with SiC based quantum photonic devices due to the maturity of SiC material and fabrication technology, the plethora of candidate quantum emitters ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
Zinc Oxynitride (ZnOxNy) thin films display high mobilities and a considerable tunability of both the free electron concentration and optical band gap. The properties achievable for this material system makes ZnOxNy an ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
The electric field dependence of emission rate of the deep traps with level near Ec−0.6 eV, so-called E1 traps, was studied by means of deep level transient spectroscopy measurements over a wide range of applied voltages. ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
Diffusion of the n-type dopant Sn in β-Ga2O3 is studied using secondary-ion mass spectrometry combined with hybrid functional calculations. The diffusion of Sn from a Sn-doped bulk substrate with surface orientation (001) ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
Pathways and energy barriers for the migration of Ga vacancies (VGa) and Ga interstitials (Gai) in β−Ga2O3 are explored using hybrid functional calculations and the nudged elastic band method. Considering β−Ga2O3 as primarily ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
Abstract The thermal stability of different Schottky contacts (Au, Pt, and Ni) on (100) β ‐Ga 2 O 3 single crystals grown by the Czochralski method is investigated. Besides the examination of the Schottky barrier parameters, ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
Defects in pulsed-laser deposition grown have been investigated using thermal admittance spectroscopy and secondary ion mass spectrometry (SIMS). A film was grown on either a tin-doped indium oxide or an aluminum-doped ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
II–IV nitrides and their alloys represent an earth-abundant and potentially cost-efficient alternative to the well-developed AlN-GaN-InN system. A major drawback with the II–IV nitrides is that ZnSnN2, the lowest band gap ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
The carrier lifetime control over 150 μm thick 4H-SiC epitaxial layers via thermal generation and annihilation of carbon vacancy (VC) related Z1/2 lifetime killer sites is reported. The defect developments upon typical SiC ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
Silicon carbide (SiC) is a wide band-gap semiconductor of great technological importance, showing promise for application areas ranging from quantum computing and communication to power devices. Vital in both the contexts ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
The influence of heat treating [Formula: see text]-type bulk [Formula: see text]-Ga[Formula: see text]O[Formula: see text] in hydrogen (H[Formula: see text]) and argon (Ar) gases on the presence of the defect level commonly ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2022)
Defect accumulation and annealing phenomena in Si-implanted monoclinic gallium oxide (β-Ga 2 O 3 ) wafers, having [Formula: see text], (010), and (001) orientations, were studied by Rutherford backscattering spectrometry ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
Abstract Semiconductor materials provide a compelling platform for quantum technologies (QT). However, identifying promising material hosts among the plethora of candidates is a major challenge. Therefore, we have developed ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
Ion implantation induced phase transformation and the crystal structure of a series of ion implanted β-Ga 2 O 3 samples were studied using electron diffraction, high resolution transmission electron microscopy, and scanning ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2022)
Electrical properties of point defects in 4𝐻-SiC have been studied extensively, but those related to carbon interstitials (Ci) have remained elusive until now. Indeed, when introduced via ion irradiation or implantation, ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
This work systematically explores 19 unique configurations of the close-associate Ga–O divacancies (VGaVO) in β−Ga2O3, including their complexes with H impurities, using hybrid functional calculations. Interestingly, most ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Silicon (Si) is an efficient n-type dopant in gallium oxide (Ga2O3)—an ultra-wide bandgap semiconductor promising in a number of applications. However, in spite of the technological importance for device fabrication, the ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract Conductive rutile TiO 2 has received considerable attention recently due to multiple applications. However, the permittivity in conductive, reduced or doped TiO 2 appears to cause controversy with reported values ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Semiconductor nanocrystals are often proposed as a viable route to improve solar energy conversion in photovoltaics and photoelectrochemical systems. Embedding the nanocrystals in, e.g. a transparent and conducting electrode ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Point defects in semiconductors are promising single-photon emitters (SPEs) for quantum computing, communication, and sensing applications. However, factors such as emission brightness, purity. and indistinguishability are ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Positron annihilation spectroscopy, Fourier transform-infrared absorption spectroscopy, and secondary ion mass spectrometry have been used to study the behavior of gallium vacancy-related defects and hydrogen in deuterium ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
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, ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Point defects in semiconductors are emerging as an important contender platform for quantum technology (QT) applications, showing potential for quantum computing, communication, and sensing. Indeed, point defects have been ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)
The effect of lattice anisotropy on the diffusion of hydrogen (H)/deuterium (2H) in β-Ga2O3 was investigated using secondary ion mass spectrometry (SIMS) and hybrid-functional calculations. Concentration-depth profiles of ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Direct evidence of N2 formation after annealing of (ZnO)1−x(GaN)x alloys was revealed. N2 was trapped by VZn+Ga-clusters, forming faceted voids along grain boundaries. This study shows that N–N bonding is a competitive ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Point defects in solids are promising single-photon sources with application in quantum sensing, computing and communication. Herein, we describe a theoretical framework for studying electric field effects on defect-related ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Single-photon emitting point defects in semiconductors have emerged as strong candidates for future quantum technology devices. In the present work, we exploit crystalline particles to investigate relevant defect localizations, ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
We have used a combination of optical absorption and electrical conductivity measurements to study the effect of the main donor on small polarons in rutile TiO2 single crystals rendered n-type conductive by hydrogenation ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Heterojunction Cu2O solar cells are an important class of Earth-abundant photovoltaics that can be synthesized by a variety of techniques, including electrochemical deposition (ECD) and thermal oxidation (TO). The latter ...
(Journal article / Tidsskriftartikkel / SubmittedVersion, 2020)
Making a systematic effort, we have developed single-crystalline ZnSnN2 on ZnO (0001) by reactive magnetron co-sputtering. Epitaxial growth was achieved at 350 °C by co-sputtering from metal targets in a nitrogen atmosphere, ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
This work explores the luminescence properties of self-trapped holes and impurity-related acceptors using one-dimensional configuration coordinate diagrams derived from hybrid functional calculations. The photoluminescence ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
The development of defect populations after proton irradiation of n-type 4H-SiC and subsequent annealing experiments is studied by means of deep level transient (DLTS) and photoluminescence spectroscopy. A comprehensive ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Cu2ZnSn(S,Se)4 is a promising nontoxic earth‐abundant solar cell absorber. To optimize the thin films for solar cell device performance, postdeposition treatments at temperatures below the crystallization temperature are ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Channeling phenomena during ion implantation have been studied for 50 keV 11 B, 100 keV 27 Al and 240 keV 71 Ga in 4H-SiC by secondary ion mass spectrometry and medium energy ion backscattering. The same projected range ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Low-energy muon-spin-rotation spectroscopy (LE-μSR) is employed to study silicon and carbon vacancies in proton-irradiated 4H-SiC. We show that the implanted muon is quickly attracted to the negative Si vacancy (VSi), where ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
The implantation of aluminum into 4H-SiC is studied using secondary ion mass spectrometry. In particular, two-dimensional concentration profiles are obtained, which allow the investigation of lateral straggling and its ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Deep-level transient spectroscopy measurements on β-Ga2O3 crystals reveal the presence of three defect signatures labeled E2a, E2b, and E3 with activation energies at around 0.66 eV, 0.73 eV, and 0.95 eV below the conduction ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
A steady-state photocapacitance (SSPC) setup directly connected to the beamline of a MeV ion implanter is utilized to study primary intrinsic defects in β–Ga2O3 generated by He implantation at cryogenic temperatures (120 ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
The optical properties of single ion tracks have been studied in ZnO implanted with Ge by combining depth-resolved hyperspectral cathodoluminescence (CL) and photoluminescence (PL) spectroscopy techniques. The results ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
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 ...
Formation and control of the E2* center in implanted b-Ga2O3 by reverse-bias and zero-bias annealing
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Deep-level transient spectroscopy measurements are conducted onβ-Ga2O3thin-filmsimplanted with helium and hydrogen (H) to study the formation of the defect levelE∗2(EA=0.71 eV) during heat treatments under an applied ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
Self-diffusion of carbon (12C and 13C) and silicon (28Si and 30Si) in 4H silicon carbide has been investigated by utilizing a structure containing an isotope purified 4H-28Si12C epitaxial layer grown on an n-type (0001) ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)
The silicon vacancy (VSi) in 4H-SiC is a room temperature single-photon emitter with a controllable high-spin ground state and is a promising candidate for future quantum technologies. However, controlled defect formation ...
Formation and control of the E2* center in implanted b-Ga2O3 by reverse-bias and zero-bias annealing
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)
Deep-level transient spectroscopy measurements are conducted on β-Ga2O3 thin-films implanted with helium and hydrogen (H) to study the formation of the defect level E2 lowast (EA = 0.71 eV) during heat treatments under an ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)
We investigate the migration mechanism of the carbon vacancy (VC) in silicon carbide (SiC) using a combination of theoretical and experimental methodologies. The VC, commonly present even in state-of-the-art epitaxial SiC ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
Reliable single-photon emission is crucial for realizing efficient spin-photon entanglement and scalable quantum information systems. The silicon vacancy (VSi) in 4H-SiC is a promising single-photon emitter exhibiting ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
Ga2O3 is a deep-UV transparent semiconducting oxide being interesting for solar-blind photo detectors e.g. for flame or missile plume detection. The bandgap of about 4.9 eV can be increased by alloying with Al2O3. We have ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)
Direct evidence of the formation of nitrogen molecules (N2) after ion implantion of ZnO has been revealed by an atomically resolved scanning transmission electron microscopy (STEM)–electron energy-loss spectroscopy (EELS) ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)
Mixed oxide hydride anion systems constitute a novel class of materials exhibiting intriguing properties such as solid-state hydride ion conduction and fast anion exchange. In this contribution we derive the kinetics of ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
Zn substitutional lithium ( Li Zn ) and sodium ( Na Zn ) acceptors and their complexes with common donor impurities ( Al Zn , Hi, and HO) in ZnO have been studied using hybrid functional calculations. The results show ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
The impact of hydrogen in ZnO is revealed by combining reaction dynamics calculations with temperature dependent Hall (TDH), photoluminescence, and secondary ion mass spectrometry measurements performed on H, 2H, and He ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
Ion implantation is an important technique in semiconductor processing and has become a key technology for 4H-SiC devices. Today, aluminum (Al) implantations are routinely used for p-type contacts, p+-emitters, terminations ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
Ion implantation is a commonly used process step in 4H-SiC device manufacturing to implement precise concentrations of dopant atoms in selected areas and depths. This paper reports on vanadium (V) implantation into ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
Ge-on-Si and Ge-on-insulator (GeOI) are the most promising materials for the next-generation nanoelectronics that can be fully integrated with silicon technology. To this day, the fabrication of Ge-based transistors with ...
(Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)
With the demand of aggressive scaling in nanoelectronics, further progress can be realized by integration of high mobility semiconductors, such as III–V compound semiconductors, with complementary metal‐oxide‐semiconductor ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
Single crystalline bulk and epitaxially grown gallium oxide (β–Ga2O3) was irradiated by 0.6 and 1.9 MeV protons to doses ranging from 5 × 109 to 6 × 1014 cm−2 in order to study the impact on charge carrier concentration ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)
The structural and optical properties of magnetron sputtered thin films of (ZnO)1−x(GaN)x deposited on zinc oxide, sapphire, and silicon oxide are studied as a function of strain accumulation and post‐deposition anneals ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
Sodium and oxygen are prevalent impurities in kesterite solar cells. Both elements are known to strongly impact performance of the kesterite devices and can be connected to efficiency improvements seen after heat treatments. ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
It is known that the behavior of residual Li in ion implanted ZnO depends on the preferential localization of the implants, in particular, forming characteristic Li depleted or Li pile-up regions for Zn or O sublattice ...
(Journal article / Tidsskriftartikkel / SubmittedVersion, 2018)
The evolution of sheet resistance of n-type In2O3 and Ga2O3 exposed to bombardment with MeV 12C and 28Si ions at 35 K is studied in situ. While the sheet resistance of Ga2O3 increased by more than eight orders of magnitude ...
(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2018)
Band gap grading of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells can be achieved by varying the Sr = [S]/([S] + [Se]) ratio in the absorber layer with depth. One approach is a two-step annealing process where the absorber is first ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
The influence of Fermi level position and annealing ambient on the zinc vacancy VZn generation and Al diffusion is studied in monocrystalline zinc oxide (ZnO). From secondary-ion mass spectrometry and positron annihilation ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
Electronic states in the upper part of the bandgap of reduced and/or hydrogenated n-type rutile TiO2 single crystals have been studied by means of thermal admittance and deep-level transient spectroscopy measurements. The ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
The aluminum–zinc-vacancy (AlZn−VZn) complex is identified as one of the dominant defects in Al-containing n-type ZnO after electron irradiation at room temperature with energies above 0.8 MeV. The complex is energetically ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2013)
We studied the structural properties, defect formation, and thermal stability of H in hydrothermally grown ZnO single crystals implanted with H- dose ranging from 2.5×1016 to 1×1017 cm−2. H implantation is found to create ...
(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2012)
The lateral distributions of intrinsic point defects in n-type (0001) 4H-SiC have been investigated following room temperature irradiation with a focused beam of 10 keV protons. Laterally resolved deep level transient ...