A5042681955- ZnO doping and properties
- Ga2O3 and related materials
- Electronic and Structural Properties of Oxides
- Ion-surface interactions and analysis
- Semiconductor materials and devices
- Copper-based nanomaterials and applications
- GaN-based semiconductor devices and materials
- Silicon and Solar Cell Technologies
- Silicon Carbide Semiconductor Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced Photocatalysis Techniques
- Metal and Thin Film Mechanics
- Thin-Film Transistor Technologies
- Nuclear materials and radiation effects
- Semiconductor materials and interfaces
- Diamond and Carbon-based Materials Research
- Quantum Dots Synthesis And Properties
- Silicon Nanostructures and Photoluminescence
- Advanced ceramic materials synthesis
- Advanced Semiconductor Detectors and Materials
- Gas Sensing Nanomaterials and Sensors
- Semiconductor Quantum Structures and Devices
- X-ray Spectroscopy and Fluorescence Analysis
- Luminescence Properties of Advanced Materials
- Photonic and Optical Devices
University of Oslo
2016-2025
Chalmers University of Technology
2024
National Centre for Nuclear Research
2019-2023
Pakistan Institute of Nuclear Science and Technology
2017
Air University
2017
University of Hong Kong
2017
Institute of Physics
2014
KTH Royal Institute of Technology
2009-2014
Peter the Great St. Petersburg Polytechnic University
2001-2010
Polytechnic University
2010
Oxygen vacancy $({V}_{\mathrm{O}})$ is a common native point defect that plays crucial roles in determining the physical and chemical properties of metal oxides such as ZnO. However, fundamental understanding ${V}_{\mathrm{O}}$ still very sparse. Specifically, whether mainly responsible for $n$-type conductivity ZnO has been unsettled past 50 years. Here, we report on study oxygen self-diffusion by conceiving growing oxygen-isotope heterostructures with delicately controlled potential Fermi...
Abstract Radiation tolerance is determined as the ability of crystalline materials to withstand accumulation radiation induced disorder. Nevertheless, for sufficiently high fluences, in all by far known semiconductors it ends up with either very disorder levels or amorphization. Here we show that gamma/beta (γ/β) double polymorph Ga 2 O 3 structures exhibit remarkably tolerance. Specifically, room temperature experiments, they tolerate a equivalent hundreds displacements per atom, without...
Polymorphism determines significant variations in materials' properties by lattice symmetry variation. If they are stacked together into multilayers, polymorphs may work as an alternative approach to the sequential deposition of layers with different chemical compositions. However, selective polymorph crystallization during conventional thin film synthesis is not trivial; changes temperature or pressure when switching from one another cause degradation structural quality. The present reports...
Disordering of solids often leads to amorphization, but polymorph transitions, facilitated by favorable atomic rearrangements, may temporarily help maintain long-range periodicity in the solid state. In far-from-equilibrium situations, such as collision cascades, these rearrangements not necessarily follow a thermodynamically gainful path, be kinetically limited. this Letter, we focus on crystallization instead amorphization cascades gallium oxide (Ga_{2}O_{3}). We determine disorder...
Nitrogen doping is a promising method of engineering the electronic structure metal oxide to modify its optical and electrical properties; however, effect strongly depends on types defects introduced. Herein, we report comparative study nitrogen-doping-induced in Cu2O. Even lightly doped samples, considerable number nitrogen interstitials (Ni) formed, accompanied by substitutions (NO) oxygen vacancies (VO). In course high-temperature annealing, these Ni atoms interacted with VO, resulting an...
Polymorphs are common in nature and can be stabilized by applying external pressure materials. The strain also induced the gradually accumulated radiation disorder. However, semiconductors, disorder accumulation typically results amorphization instead of engaging polymorphism. By studying these phenomena gallium oxide we found that may prominently suppressed monoclinic to orthorhombic phase transition. Utilizing this discovery, a highly oriented single-phase film on top substrate was...
Defect accumulation and annealing phenomena in Si-implanted monoclinic gallium oxide (β-Ga2O3) wafers, having (2¯01), (010), (001) orientations, were studied by Rutherford backscattering spectrometry channeling mode (RBS/c), x-ray diffraction (XRD), (scanning) transmission electron microscopy [(S)TEM]. Initially, the samples with different surface orientations implanted 300 keV 28Si+-ions, applying fluences range of 1 × 1014–2 1016 Si/cm2, unveiling interesting disorder kinetics. In...
In situ TEM heating studies of double γ/β-Ga 2 O 3 polymorph structures revealed γ-to-β transition via the formation β-Ga domains.
Abstract Gallium oxide (Ga 2 O 3 ) can be crystallized in several polymorphs exhibiting different physical properties. In this work, polymorphic structures consisting of the cubic defective spinel (γ) film on top monoclinic (β) substrate are fabricated by disorder‐induced ordering, known to a practical way stack these together. Such bilayer annealed investigate optical properties and phase transformations. Specifically, photoluminescence diffuse reflectance spectroscopy combined with...
A phenomenon of wurtzite (w), zincblende (zb), and rock-salt (rs) phase separation was investigated in ZnCdO films having Cd contents the range 0%--60% settling a discussion on stability issues ZnCdO. First, low-Cd-content (\ensuremath{\leqslant}17%) realized preferentially w matrix determining optimal Zn-lean conditions by tuning precursor decomposition rates during synthesis. However, more detailed analysis x-ray diffraction photoluminescence (PL) data revealed that single-phase is likely...
Implanted atoms can affect the evolution of ion-induced defects in radiation hard materials exhibiting a high dynamic annealing and these processes are poorly understood. Here, we study thermal structural wurtzite ZnO samples implanted at room temperature with wide range ion species (from 11B to 209Bi) doses up 2 × 1016 cm−2. The disorder was characterized by combination Rutherford backscattering spectrometry, nuclear reaction analysis, transmission electron microscopy, while secondary mass...
This study presents the novel peridynamic constitutive relations formulated in order to predict plastic deformation and damage evolution irradiated materials. The behaviour of material which radiation induced defects contribute defined porosity is described by Gurson–Tvergaard–Needleman (GTN) yield criterion with irradiation hardening. definition proposed as a volume discontinuities created particles. new for hardening based on dilatational part elastic strain energy are formulated. physical...
This paper reports an innovative process to fabricate $\beta$-Ga$_{2}$O$_{3}$ microtubes and nanomembranes based on ion implantation in (100)-oriented single-crystals. We show that, under specific flux fluence conditions, the irradiation-induced strain profile promotes detachment rolling-up of a thin surface layer, forming microtube. The strain-disorder interplay was investigated detail for Cr-implanted with range complementary methods, showing excellent agreement between experimental...
Ion bombardment provides an opportunity to study basic properties of intrinsic defects in materials since the radiation-induced disorder accumulation depends on balance between defect generation and migration rates. In particular, variation such parameters as irradiation temperature ion flux, known literature dose-rate effect, interconnects macroscopically measured lattice with barrier dominating defects. this work, we effect monoclinic gallium oxide (β-Ga2O3) extracted its activation energy...
Ion irradiation is a powerful tool to tune properties of semiconductors and, in particular, gallium oxide (Ga2O3) which promising ultra-wide bandgap semiconductor exhibiting phase instability for high enough strain/disorder levels. In the present paper we observed an interesting interplay between disorder and strain monoclinic \b{eta}-Ga2O3 single crystals by comparing atomic cluster ion irradiations as well ions co-implants. The results obtained combination channeling technique, x-ray...
Ion beam fabrication of metastable polymorphs Ga2O3, assisted by the controllable accumulation disorder in lattice, is an interesting alternative to conventional deposition techniques. However, adjustability electrical properties such films unexplored. In this work, we investigated two strategies for tuning electron concentration ion created κ-polymorph: adding silicon donors implantation and hydrogen via plasma treatments. Importantly, all heat treatments were limited ≤600 °C, set thermal...
In this study, the results of hydrogen plasma treatments β-Ga2O3, α-Ga2O3, κ-Ga2O3 and γ-Ga2O3 polymorphs are analyzed. For all polymorphs, strongly suggest an interplay between donor-like configurations acceptor complexes formed by with gallium vacancies. A strong anisotropy effects in most thermodynamically stable β-Ga2O3 explained its low-symmetry monoclinic crystal structure. metastable, α-, κ- γ-polymorphs, it is shown that net result hydrogenation often a increase density centers...
Disordering of solids typically leads to amorphization, but polymorph transitions, facilitated by favorable atomic rearrangements, may temporarily help maintain long-range periodicity in the solid state. In far-from-equilibrium situations, such as collision cascades, these rearrangements not necessarily follow a thermodynamically gainful path, be kinetically limited. this Letter, we focused on crystallization instead amorphization cascades gallium oxide (\ce{Ga2O3}). We determined disorder...