A5022345489- Semiconductor Quantum Structures and Devices
- GaN-based semiconductor devices and materials
- Spectroscopy and Laser Applications
- Semiconductor Lasers and Optical Devices
- Silicon Nanostructures and Photoluminescence
- Terahertz technology and applications
- Nanowire Synthesis and Applications
- Photonic and Optical Devices
- Ga2O3 and related materials
- Semiconductor materials and interfaces
- Atmospheric aerosols and clouds
- Thermal Radiation and Cooling Technologies
- Quantum and electron transport phenomena
- Plasmonic and Surface Plasmon Research
- Advanced Semiconductor Detectors and Materials
- Advancements in Semiconductor Devices and Circuit Design
- Optical properties and cooling technologies in crystalline materials
- Quantum Dots Synthesis And Properties
- Semiconductor materials and devices
- Acoustic Wave Resonator Technologies
- Photonic Crystals and Applications
Center for Physical Sciences and Technology
2020-2023
Linköping University
2019-2020
Peter the Great St. Petersburg Polytechnic University
2013-2019
This article discusses specific quantum transitions in a few-particle hole gas, localized strongly oblate lens-shaped dot. Based on the adiabatic method, possibility of realizing generalized Kohn theorem such system is shown. The criteria for implementation this dot, fulfilled experiment, presented. An analytical expression obtained frequencies resonant absorption far-infrared radiation by gas heavy holes, which depends geometric parameters results experiments arrays p-doped Ge/Si dots grown...
Dispersion characteristics of hybrid surface plasmon-phonon-polaritons (SPPhPs) on the air/polar semiconductor interface were investigated by means shallow relief grating using emission spectroscopy methods. A set structures with optimal 1 µm depth and periods from 8 to 22 was developed a heavily-doped GaN crystal. The SPPhPs excited thermal heating or electrical biasing samples which radiated directive polarized features in an extremely narrowband spectrum range. Detailed analysis damping...
The n-type GaN epilayers with low electron density were developed on a native substrate using the metalorganic vapour phase epitaxy method and investigated under pulsed electric fields until material breakdown optically in spectrum range from 0.1 THz to 60 at two temperatures of 77 K 300 K. demonstrated low-field mobility values reaching up 1021 cm2/V·s 1.06 × 1016 cm-3 (at K) 2652 0.21 K), respectively. Maximum injected power value till damage epilayer was found be 1.8 GW/cm3 5.1 K, results...
We report the growth of dilute nitride GaNAs and GaInNAs core-multishell nanowires (NWs) using molecular beam epitaxy assisted by a plasma source. Using self-catalyst vapor-liquid-solid mode, these NWs were grown on Si(111) silicon insulator substrates. The shells contain nitrogen up to 3%. Axial cross-sectional scanning transmission electron microscopy measurements energy-dispersive x-ray spectrometry confirm formation NW structure. obtained high-quality with compositions 2%. On other hand,...
Abstract Core/shell nanowire (NW) heterostructures based on III-V semiconductors and related alloys are attractive for optoelectronic photonic applications owing to the ability modify their electronic structure via bandgap strain engineering. Post-growth thermal annealing of such NWs is often involved during device fabrication can also be used improve optical transport properties. However, effects alloy disorder in core/shell not fully understood. In this work we investigate these novel...
Electro-optical modulation of a terahertz beam by drifting space-charge domains in n-GaN epilayers under pulsed electric field excitation was found and investigated at temperature 77 K. The free charge carrier contribution observed as the attenuation (THz) transmission whose value independently on THz polarization increased with field, presence domains, up to 10%. electro-optical contribution, other hand, sensitive demonstrated nonlinear increase 50% external 1.6 kV/cm, while higher values...
Formation and drift of space-charge domains with velocity sound were experimentally observed in charge current traces a high-quality lightly doped GaN semiconductor under pulsed electric fields at room liquid nitrogen temperatures. A epilayer was developed on an Ammono substrate to achieve the electron density low-field mobility values 1.06 × 1016 cm−3 1021 cm2/V s (at 300 K) 0.21 2652 77 K), respectively. The formation moving only samples lengths 1 mm longer arising critical starting from...
Abstract We report on optimization of growth conditions GaAs/GaNAs/GaAs core/shell/shell nanowire (NW) structures emitting at ∼1 μ m, aiming to increase their light efficiency. A slight change in temperature is found critically affect optical quality the active GaNAs shell and shown result from suppressed formation non-radiative recombination (NRR) centers under optimum temperature. By employing optically detected magnetic resonance spectroscopy, we identify gallium vacancies interstitials...
Cathodoluminescence (CL) and micro-photoluminescence spectroscopies are employed to investigate effects of structural defects on carrier recombination in GaNAsP nanowires (NWs) grown by molecular beam epitaxy Si substrates. In the NWs with a low N content 0.08%, these found promote non-radiative (NR) recombination, which causes spatial variation CL peak position its intensity. Unexpectedly, detrimental can be suppressed even small increase nitrogen composition from 0.08% 0.12%. This is...
Beaming and coherent thermal emission of the hybrid surface plasmon phonon polaritons (SPPhPs) was numerically experimentally investigated employing n-GaN relief gratings (SRGs) shaped in a linear radial geometry. The polariton propagation losses were minimized with help rigorous coupled wave analysis model, while spatial temporal quality selected mode radiation normal direction maximized by fixing grating period value at 17.5 µm varying filling factor from 75% to 25%. A set optimal design...
We report three approaches to development of electrically-pumped THz emitters based on III-Nitride structures. The first approach entails the investigation two-dimensional (2D) plasmons in grating-gated AlGaN/GaN heterostructures performed at temperatures above liquid nitrogen by means time-domain spectroscopy (TDS). Comparative analysis experimental data revealed considerable phase shift transmitted pulses resonant frequencies collective oscillations 2D electron gas (2DEG). use is proposed...
The influence of the lateral electric field on mid-infrared intersubband light absorption and near-infrared interband photoluminescence is experimentally investigated in tunnel-coupled GaAs/AlGaAs quantum wells. Absorption emission modulation are related to electron heating redistribution hot electrons between well states resulting variation space charge structure.
Spectra of variation intersubband light absorption induced by lateral electric field and lattice temperature change were studied in the structure with double GaAs/AlGaAs quantum wells. The calculated positions energy levels have been verified interband photoluminescence measurements. under was explained redistribution hot charge carriers between two lowest electronic states subsequent emergence space