A5069895539- ZnO doping and properties
- Electron and X-Ray Spectroscopy Techniques
- Electronic and Structural Properties of Oxides
- Quantum Dots Synthesis And Properties
- Advanced Electron Microscopy Techniques and Applications
- Chalcogenide Semiconductor Thin Films
- Ga2O3 and related materials
- Copper-based nanomaterials and applications
- Perovskite Materials and Applications
- Silicon Nanostructures and Photoluminescence
- Heusler alloys: electronic and magnetic properties
- Semiconductor materials and interfaces
- Luminescence Properties of Advanced Materials
- GaN-based semiconductor devices and materials
- Surface and Thin Film Phenomena
- Advancements in Solid Oxide Fuel Cells
- Advanced Condensed Matter Physics
- 2D Materials and Applications
University of Oslo
2017-2021
Norwegian University of Science and Technology
2014
Mixed oxide hydride anion systems constitute a novel class of materials exhibiting intriguing properties such as solid-state ion conduction and fast exchange. In this contribution we derive the kinetics transport in mixed oxide-hydride system, SrTiO3- xH x, through isotope exchange depth profiling. Density functional theory (DFT) calculations indicate that migration H- to neighboring vacant oxygen lattice sites is fast, but long-range impeded by slow reorganization sublattice. From measured...
The combination of high optical transparency and low electrical resistivity has made transparent conductive oxides (TCOs) a key technology in many optoelectronic applications. Furthermore, the study TCOs yields insight into fundamental parameters semiconductors. For example, charge carrier concentration results an apparent shift band gap, so-called Burstein-Moss shift, addition to plasmonic resonances near infrared regime. While both effects are related structure, their lateral distribution...
Using monochromated electron energy loss spectroscopy in a probe-corrected scanning transmission microscope we demonstrate band gap mapping ZnO/ZnCdO thin films with spatial resolution below 10 nm and spectral precision of 20 meV.
It is known that ${(\mathrm{ZnO})}_{1\ensuremath{-}x}{(\mathrm{GaN})}_{x}$ alloys demonstrate remarkable energy band bowing, making the material absorb in visible range, spite of binary components being classical wide gap semiconductors. However, origin this bowing not settled; two major mechanisms are under debate: Influence orbital repulsion and/or formation a defect band. In present work, we applied combination absorption and emission measurements on samples exhibiting an outstanding...
The optical band gap of ZnO has been measured as a function temperature using Electron Energy-Loss Spectroscopy (EELS) in (Scanning) Transmission Microscope ((S)TEM) from approximately 100 K up towards 1000 K. narrowing shows close to linear dependency for temperatures above 250 and is accurately described by Varshni, Bose-Einstein, Pässler Manoogian-Woolley models. Additionally, the compared with both absorption measurements photoluminescence data. STEM-EELS here shown be viable technique...
We have investigated how layered structures of TiO2 and Eu2O3 on the subnanometer scale control optical absorption, energy transfer, emission quenching mechanisms in sensitized lanthanide luminescence systems. By using atomic layer deposition (ALD) as a tool for designing materials with sub nanometer precision, we been able to make ranging from separate (TiO6)8- clusters bulk TiO2, series samples showing transitions 3D 2D migration. Photoluminescence, excitation decay measurements used...
Functionalizing transparent conducting oxides (TCOs) is an intriguing approach to expand the tunability and operation of optoelectronic devices. For example, forming nanoparticles that act as quantum wells or barriers in zinc oxide (ZnO), one main TCOs today, may its optical electronic tunability. In this work, 800 keV Ge ions have been implanted at a dose 1 × 1016 cm−2 into crystalline ZnO. After annealing 1000 °C embedded disk-shaped particles with diameters up 100 nm are formed. Scanning...
Semiconductor nanocrystals are often proposed as a viable route to improve solar energy conversion in photovoltaics and photoelectrochemical systems.Embedding the in, e.g., transparent conducting electrode of cell will promote photon absorption subsequent transfer generated charge carriers from nanocrystal, thereby enhance function electrode.This can be accomplished by embedding semiconducting nanocrystal with small bandgap oxide (TCO), which is commonly utilized new generation cells.Here,...
We respond to the comment by Thomas Walther and reaffirm findings of our original article.