A5064322540- ZnO doping and properties
- Nanowire Synthesis and Applications
- GaN-based semiconductor devices and materials
- Ga2O3 and related materials
- Semiconductor Quantum Structures and Devices
- Electronic and Structural Properties of Oxides
- Copper-based nanomaterials and applications
- Quantum Dots Synthesis And Properties
- Gas Sensing Nanomaterials and Sensors
- Chalcogenide Semiconductor Thin Films
- Semiconductor materials and devices
- Perovskite Materials and Applications
- Advancements in Semiconductor Devices and Circuit Design
- Magnetic and transport properties of perovskites and related materials
- Advanced Photocatalysis Techniques
- Cancer Treatment and Pharmacology
- Catalytic Processes in Materials Science
- Photonic and Optical Devices
- Acoustic Wave Resonator Technologies
- Mechanical and Optical Resonators
- Luminescence Properties of Advanced Materials
- Electron and X-Ray Spectroscopy Techniques
- Isotope Analysis in Ecology
- Quantum and electron transport phenomena
- 2D Materials and Applications
Linköping University
2014-2024
Justus-Liebig-Universität Gießen
2006-2012
ZnO powder heat treated in $\mathrm{N}{\mathrm{H}}_{3}$ atmosphere was investigated by electron paramagnetic resonance, photoluminescence, and Raman spectroscopy. We find that the treatment creates Zn interstitials (${\mathrm{Zn}}_{i}$) complexes of nitrogen atoms substituting oxygen $({\mathrm{Zn}}_{i}\text{\ensuremath{-}}{\mathrm{N}}_{\mathrm{O}})$. A correlation between ${\mathrm{Zn}}_{i}$ an exciton at $3.366\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ $({\mathrm{I}}_{3})$ can be stated a...
Zinc oxide (ZnO) is one of the most promising transparent conducting oxides for use in electronics, but to realize its potential we must better understand how semiconductor physics depends on material properties, particularly interaction defects with dopants. This study identifies Al${}_{Z\phantom{\rule{0}{0ex}}n}$-${V}_{Z\phantom{\rule{0}{0ex}}n}$ complex as a defect crucial and general importance that limits $n$-type doping efficiency thus performance ZnO. Similar effects are anticipated...
We present a systematic analysis of the structural properties Mn implanted ZnO by Raman scattering and complementary methods in composition range 0.2–8 at.% (relative to Zn) with an implantation step profile about 300 nm depth. ions are substitutionally incorporated on Zn sites wurtzite lattice no secondary phases detected. Beside common eigenmodes host lattice, we observe additional modes related implantation, which studied for different concentrations annealing procedures. distinguish...
Nanowire (NW) lasers operating in the near-infrared spectral range are of significant technological importance for applications telecommunications, sensing, and medical diagnostics. So far, lasing within this has been achieved using GaAs/AlGaAs, GaAs/GaAsP, InGaAs/GaAs core/shell NWs. Another promising III-V material, not yet explored its capacity, is dilute nitride GaNAs. In work, we demonstrate, first time, optically pumped from GaNAs shell a single GaAs/GaNAs NW. The characteristic...
The possibility to engineer nanowire heterostructures with large bandgap variations is particularly interesting for technologically important broadband photodetector applications. Here we report on a combined study of design, fabrication, and optoelectronic properties infrared photodetectors comprising four million n+-i-n+ InP nanowires periodically ordered in arrays. were grown by metal-organic vapor phase epitaxy substrates, either single or 20 InAsP quantum discs embedded the i-segment....
Photon upconversion materials are attractive for a wide range of applications from medicine, biology, to photonics. Among them, ZnO is particular interest owing its outstanding combination and physical properties. Though energy has been demonstrated in ZnO, the exact mechanism still unknown, preventing control processes. Here, defects formed bulk nanostructured synthesized using standard growth techniques play key role promoting efficient via two‐step two‐photon absorption (TS‐TPA). From...
β-Ga2O3 is a wide bandgap semiconductor that attractive for various applications, including power electronics and transparent conductive electrodes. Its properties can be strongly affected by transition metal impurities commonly present during the growth such as Cr. In this Letter, we determine electronic structure of Cr3+ performing correlative study magneto-photoluminescence (magneto-PL) electron paramagnetic resonance. We unambiguously prove so-called R1 R2 PL lines at around 1.79 eV...
The authors report the synthesis of nanoporous ZnO, which exhibits a periodically ordered, uniform pore system with crystalline walls. structure is investigated by x-ray diffraction, transmission electron microscopy, and selected area diffraction. large specific surface uniformity are confirmed nitrogen physisorption. Raman spectroscopy along low-temperature photoluminescence measurements confirms high degree crystallinity gives insight into defects participating in radiative recombination processes.
Comprehensive characterization of defects formed in bulk ZnO single crystals co-implanted with N and Zn as well O atoms is performed by means optically detected magnetic resonance (ODMR) complemented Raman photoluminescence (PL) spectroscopies. It shown that addition to intrinsic such vacancies interstitials, several N-related are the implanted ZnO. The prevailed configuration found depend on choices co-implants also chosen annealing ambient. Specifically, co-implantation leads formation (i)...
Plasmonic response of free charges confined in nanostructures plasmonic materials is a powerful means for manipulating the light-material interaction at nanoscale and hence has influence on various relevant technologies. In particular, responsive mid-infrared range are technologically important as home to vibrational resonance molecules also thermal radiation hot objects. However, development field practically challenged with lack low-loss supporting high quality plasmons this spectrum....
Recombination processes in GaP/GaNP core/shell nanowires (NWs) grown on a Si substrate by molecular beam epitaxy are examined using variety of optical characterization techniques, including cw- and time-resolved photoluminescence optically detected magnetic resonance (ODMR). Superior quality the structures is demonstrated based observation intense emission from single NW at room temperature. This shown to originate radiative transitions within N-related localized states. From ODMR, growth...
Recent developments in fabrication techniques and extensive investigations of the physical properties III–V semiconductor nanowires (NWs), such as GaAs NWs, have demonstrated their potential for a multitude advanced electronic photonics applications. Alloying with nitrogen can further enhance performance extend device functionality via intentional defects heterostructure engineering GaNAs GaAs/GaNAs coaxial NWs. In this work, it is shown that incorporation NWs leads to formation...
Nanoparticles (NPs) elicit sterile inflammation, but the underlying signaling pathways are poorly understood. Here, we report that human monocytes particularly vulnerable to amorphous silica NPs, as evidenced by single-cell-based analysis of peripheral blood mononuclear cells using cytometry time-of-flight (CyToF), while silane modification NPs mitigated their toxicity. Using THP-1 a model, observed cellular internalization nanoscale secondary ion mass spectrometry (nanoSIMS) and this was...
Abstract One-dimensional ZnO nanowires (NWs) are a promising materials system for variety of applications. Utilization ZnO, however, requires good understanding and control material properties that largely affected by intrinsic defects contaminants. In this work we provide experimental evidence unintentional incorporation nitrogen in NWs grown rapid thermal chemical vapor deposition, from electron paramagnetic resonance spectroscopy. The incorporated atoms concluded to mainly reside at...
Random arrangements of ferromagnetic MnAs nanoclusters were deposited on (111)B-GaInAs surfaces by standard metal-organic vapor-phase epitaxy (MOVPE). Ordered and cluster chains obtained selective-area MOVPE prepatterned (111)B-GaAs substrates. This new method enables one to control the arrangement in growth process offering interesting opportunities tune properties individual clusters as well interaction between carriers surrounding semiconductor matrix clusters. The magnetic anisotropy was...
We report on identification and control of important nonradiative recombination centers in GaNP coaxial nanowires (NWs) grown Si substrates an effort to significantly increase light emitting efficiency these novel nanostructures promising for a wide variety optoelectronic photonic applications. A point defect complex, labeled as DD1 consisting P atom with neighboring partner aligned along crystallographic ⟨111⟩ axis, is identified by optically detected magnetic resonance dominant center that...
Gallium oxide (b-Ga2O3) is a wide-bandgap compound semiconductor with bandgap of ~ 4.9 eV that currently considered promising for wide range applications ranging from transparent conducting electrodes to UV optoelectronic devices and power electronics. However, all these require reliable precise control electrical optical properties the material, which can be largely affected by impurities, such as transition metals commonly present during growth. In this work we employ electron paramagnetic...
Abstract We study the interaction of hydrogen donors and Lithium acceptors in bulk ZnO by electron paramagnetic resonance photoluminescence. With increasing diffusion temperature number increases whereas deep Li decreases. In range between 450 600 °C a shallow related acceptor is formed. The very same defect found diffused ZnO, epitaxial thin films in‐situ doping with Li. suggest tentative model for whereby would be an essential part core. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
We investigated the substitutional nitrogen center in ZnO single crystals by electron paramagnetic resonance (EPR) and photo-EPR spectroscopy. Aside three principle hyperfine lines due to interaction of N0 (2p5) spin with nucleus (I = 1, natural abundance 99.6%), we identify additional satellite which arise from ΔmS ±1 ΔmI ±1, ±2 transitions becoming allowed quadrupole interaction. The coupling constant e2qQ/h is determined −5.9 MHz an asymmetry parameter η 0.05. These values are somewhat...
Optically detected magnetic resonance (ODMR) complemented by photoluminescence measurements is used to evaluate optical and defect properties of ZnO nanowires (NWs) grown rapid thermal chemical vapor deposition. By monitoring visible emissions, several grown-in defects are revealed attributed Zn vacancies, shallow (but not effective mass) donor exchange-coupled pairs vacancies interstitials. It also found that the intensity donor-related ODMR signals substantially lower in NWs compared with...
Semiconductor nanowires (NWs) are attracting increasing interest as nanobuilding blocks for optoelectronics and photonics. A novel material system that is highly suitable these applications GaNP NWs. In this article, we show individual GaP/GaNP core/shell grown by molecular beam epitaxy on Si substrates can act Fabry‐Perot (FP) microcavities. This conclusion based results of microphotoluminescence (μ‐PL) measurements performed NWs, which reveal periodic undulations the PL intensity follow an...