A5018530016- Semiconductor Quantum Structures and Devices
- Advanced Semiconductor Detectors and Materials
- Semiconductor Lasers and Optical Devices
- Terahertz technology and applications
- Magnetic and transport properties of perovskites and related materials
- Spectroscopy and Laser Applications
- ZnO doping and properties
- Quantum Dots Synthesis And Properties
- Superconducting and THz Device Technology
- Electronic and Structural Properties of Oxides
- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- GaN-based semiconductor devices and materials
- Molecular Junctions and Nanostructures
- Photonic and Optical Devices
- Thermal Radiation and Cooling Technologies
- Semiconductor materials and interfaces
- Quantum and electron transport phenomena
- Advanced Fiber Laser Technologies
- Advanced Chemical Physics Studies
- Surface and Thin Film Phenomena
- Multiferroics and related materials
- Gas Sensing Nanomaterials and Sensors
- Metamaterials and Metasurfaces Applications
- Rare-earth and actinide compounds
Center for Physical Sciences and Technology
2016-2025
Vilnius University
2011-2025
Nonlinear Control Strategies (United States)
2022
Institute of Physics
2003-2005
Polish Academy of Sciences
2003-2005
Lithuanian Academy of Sciences
1992
An in situ transmission electron microscopy study of Bi quantum dot (QD) formation an annealed GaAsBi/AlAs multiple well (MQW) structure is presented this work. The investigated structure, containing two GaAsBi QWs and embedded AlGaAs parabolic barrier (PQB), was grown on semi-insulating GaAs (100) transferred onto heating holder (DENS solutions) heated up to 650 °C. Sample evolution continuously recorded bright-field STEM mode. analysis revealed that QD occurs at lower annealing...
Single‐ and multi‐quantum well (QW) structures of Ga(AsBi)/GaAs with up to 10% Bi were grown by molecular beam epitaxy (MBE) at 300–330°C substrate temperature. The photoluminesce measurements QW demonstrated room temperature emission wavelengths ∼1.43 μm. In the obtained using a combined growth approach – an active layer three QWs ∼6% was MBE, whereas (AlGa)As claddings metal organic vapour phase technique lasing 1060 nm documented.
InyGa1-yAs1-xBix layers on InP:Fe (100) substrates have been grown by molecular beam epitaxy. Up to 7% of Bi incorporation has confirmed optical and structural analyses samples. Photoluminescence signals at wavelengths up 3 µm observed, implying be a prospective material for mid-infrared applications. A weak band-gap temperature sensitivity Bi-containing InGaAs evaluated from absorption measurements.
A combined growth approach involving both molecular-beam epitaxy and metal-organic vapor phase has been developed to fabricate GaAsBi/GaAs-based quantum well (QW) laser structures with a Bi composition up 8%. Lasing operation demonstrated at room temperature 1.06 μm in diodes containing 3QWs that turn contain approximately 6% Bi. 5QW device lasing 1.09 80 K. Using temperature- pressure-dependent measurements of stimulated emission as pure spontaneous measurements, we show the threshold...
We explore quantum well laser diodes based on two material systems, classical AlGaAs, and a rather exotic GaAsBi, with lasing at around 800 nm 1100 nm, respectively for applications in pulse oximetry. These spectral regions families were selected due to closely matched effective penetration depth into soft tissue. An improved design of the band structure device active areas was tested both yielding enhancement main parameters, output power threshold current. A maximum emission AlGaAs diode...
We explore quantum well laser diodes for applications in pulse oximetry based on two material systems, namely, classical AlGaAs and a rather exotic GaAsBi, with lasing at around 800 nm 1100 nm, respectively. These spectral regions families were selected due to their closely matched effective penetration depths into soft tissue. An improved design of the band structure device active areas was tested both yielding enhancement main parameters, output power threshold current. A maximum emission...
Formation of bismuth nanocrystals in GaAsBi layers grown by molecular beam epitaxy at 330 °C substrate temperature and post-growth annealed 750 is reported. Superlattices containing alternating 10 nm-thick AlAs were on semi-insulating GaAs substrate. have served as diffusion barriers for Bi atoms, the size nanoclusters which nucleated after sample annealing was correlating with thickness bismide layers. Energy-dispersive spectroscopy Raman scattering measurements evidenced that nanoparticles...
Influence of barrier material and structure on carrier quantum confinement in GaAsBi wells (QWs) is studied comprehensively. Single- multi-QW structures were grown using solid-state molecular beam epitaxy with conventional rectangular, step-like parabolically graded AlGaAs designs. It was discovered that room temperature photoluminescence increased by more than 50 times the QWs barriers (PGBs) if compared to standard rectangular structures. The enhancement reproducible within range growth...
We report on the fabrication of ZnO:N by thermal oxidation sputter-deposited zinc nitride. Through optimising several technological steps we achieved p-type conductivity with carrier concentration in mid 1017 cm–3 range and mobility ∼10 cm2/Vs. PL spectra films show a sharp peak at 3.36 eV, most likely due to neutral acceptor bound excitons. The transmittance p-ZnO:N whole visible spectrum is ∼80 % making it suitable for transparent electronics. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Terahertz (THz) pulse generation from p-InAs, p-InSb, and n-InSb epitaxial layers are investigated using 1.55-μm wavelength femtosecond laser pulses for photoexcitation. The samples of (111) crystallographic orientation resulting in anisotropic photoconductivity. Experiments have shown that THz InAs is mainly due to photocurrent the surface electric field while a dominant mechanism InSb optical rectification. At high excitation fluencies, more efficient than p-InAs. In presence an external...
The experimental THz-excitation spectroscopy technique for determining heterojunction band offsets is suggested. When photoexcited electrons gain sufficient energy to pass the potential barrier corresponding a conduction offset, an amplitude of THz-emission pulse sharply increases, which allows direct measurements offset value. applied GaAsBi-GaAs offsets. deduced has about 45% gap difference at Bi concentrations x < 0.12 investigated.
Abstract The distribution of alloyed atoms in semiconductors often deviates from a random which can have significant effects on the properties materials. In this study, scanning transmission electron microscopy techniques are employed to analyze Bi several distinctly MBE grown GaAs 1−x x alloys. Statistical quantification atomic-resolution HAADF images, as well numerical simulations, interpret contrast Bi-containing columns at atomically abrupt (001) GaAs-GaAsBi interface and onset CuPt-type...
Abstract The influence of thermal annealing on optical properties and carrier lifetime dilute GaBi x As 1‐x layers was investigated. Thick (0.5‐1.5 μm) relaxed thin (30‐100 nm) strained bismide were grown onto semi‐insulating (100)‐oriented GaAs substrates by molecular beam epitaxy (MBE) using As4 As2, respectively. post‐growth carried out in the rapid (RTA) oven at temperatures ranging from 550 °C to 750 under nitrogen atmosphere. high resolution X‐ray diffraction (HRXRD), photoluminescence...