A5102801432- Semiconductor Quantum Structures and Devices
- Silicon Nanostructures and Photoluminescence
- Photonic and Optical Devices
- Semiconductor materials and interfaces
- Semiconductor Lasers and Optical Devices
- Advanced Semiconductor Detectors and Materials
- Quantum Dots Synthesis And Properties
- Quantum and electron transport phenomena
- Photonic Crystals and Applications
- Nanowire Synthesis and Applications
- Semiconductor materials and devices
- Terahertz technology and applications
- Spectroscopy and Laser Applications
- Magnetic properties of thin films
- Surface and Thin Film Phenomena
- Atomic and Molecular Physics
- Advanced Photonic Communication Systems
- Optical Coatings and Gratings
- Optical Coherence Tomography Applications
- Silicon and Solar Cell Technologies
- Physics of Superconductivity and Magnetism
- Superconducting and THz Device Technology
- Advancements in Semiconductor Devices and Circuit Design
- Matrix Theory and Algorithms
- Molecular Junctions and Nanostructures
Max Planck Institute of Microstructure Physics
2004-2022
OSRAM (Germany)
2017-2020
Institute for Physics of Microstructures
2010-2017
Martin Luther University Halle-Wittenberg
2014
Russian Academy of Sciences
2002-2013
Max Planck Society
2003-2011
Saint Petersburg Academic University
2011
Institute for Analytical Instrumentation
2000-2007
Physico-Technical Institute
2000-2007
Ioffe Institute
2003-2004
A study of the bandgap character compressively strained GeSn0.060-0.091/Ge(001) quantum wells grown by molecular beam epitaxy is reported. The built-in strain in GeSn leads to an increased separation between L and Γ conduction band minima. prevalent indirect interband transitions were probed photoluminescence spectroscopy. As a result we could simulate L-valley bowing parameter alloys, bL = 0.80 ± 0.06 eV at 10 K. From this conclude that even GeSn/Ge(001) alloys become direct gap...
We report on the synthesis of a novel optoelectronic material, Sn-rich Ge1–xSnx nanocrystals in Ge matrix. The have been formed after annealing metastable Ge-rich Ge1–ySny film, which was embedded Electron microscopy investigations revealed that these possess two lattice types: (i) diamondlike cubic structure with high Sn fraction (x > 0.5) and (ii) an ordered zincblende = 0.5).
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...
Abstract The luminescence properties of highly strained, Sb-doped Ge/Si multi-layer heterostructures with incorporated Ge quantum dots (QDs) are studied. Calculations the electronic band structure and measurements prove existence an electron miniband within columns QDs. Miniband formation results in a conversion indirect to quasi-direct excitons takes place. optical transitions between states hole QDs responsible for intense 1.4–1.8 µm range, which is maintained up room temperature. At 300...
Abstract We report on a way to grow very small Ge islands (basis about 15 nm, height 1 density 2 × 10 11 cm –2 ) Si substrate by molecular beam epitaxy. By the deposition of lowest amounts antimony prior we could influence formation kinetics islands. After covering layer samples show pronounced photoluminescence at room temperature in range 1.5 μm. The results optical spectroscopy experiments are interpreted this that these nanoislands quantum confinement, and therefore, they can be regarded...
A criterion for the growth of Stranski–Krastanov islands mediated by surfactants is obtained. It involves that decrease island nucleation barrier. Thereby, at a low coverage (θ ≪ 1 mono layer) facilitate formation. At high ≈ might be still facilitated, but also hampered under special conditions. The latter caused reduction ad-atom surface diffusion. We report on non-monotonic dependence Ge/Si(100) array density Sb and discuss it in frame obtained criterion.
Coupled pairs of InAs quantum dots are grown by molecular-beam epitaxy. Structural and optical characterization is done means transmission electron microscopy photoluminescence, respectively. Photoluminescence spectra consist at least three well-separated transitions that assigned to molecular energy terms a substantial exciton lifetime increase observed. Detailed spectral analysis the transient luminescence behavior indicates “intraterm” could be favorably used for creation midinfrared...
Abstract The temperature dependence of morphological characteristics Ge/Si(100) quantum dots grown by molecular beam epitaxy with constant growth rate at different substrate temperatures is investigated. mean lateral size 6.2 ML shown to increase rising temperature. Comparison experimental and theoretical results obtained in the frame kinetic model performed.
Optoelectronic properties of vertically stacked InAs∕GaAs quantum dot (QD) arrays are analyzed. The grown by molecular beam epitaxy into the intrinsic region GaAs p-i-n junctions. structures extensively characterized transmission electron microscopy and steady-state transient photoluminescences. application an external bias along growth direction is found to substantially impact photoluminescence properties. Our results allow for establishing a semiquantitative model band structure biased QD...
In this paper, we report on photoluminescence studies of a multiple quantum well Ge/GaAs heterostructure grown by laser-assisted sputtering. A broad luminescence peak is found at about 1.3 μm room temperature. We attribute to the direct band gap transitions between Γ-valley electrons in GaAs matrix and valence heavy holes Ge wells.
The spectral and polarization dependences of intraband light absorption in n- p-doped structures with InAs/GaAs quantum dots covered by InGaAs layers were studied experimentally theoretically. transmittance p- s-polarized mid-infrared radiation was a multi-pass sample geometry. Elastic strain, piezoelectric fields complex valence band structure taken into account calculations the energy spectrum, carrier wavefunctions optical matrix elements. determined value cross section corresponding to...
We investigate self-assembled pyramid-shaped Ge Quantum Dots (QDs) with lateral dimensions of 15 nm, and heights 2.5-3 nm. These QDs were grown by Molecular Beam Epitaxy (MBE) on n-type Si(100) substrates using the Sb-mediated growth mode. The resistivity was about 5 Ωcm. Si buffer layer below capping above them doped up to 10 18 cm -3 Sb. Cross-section transmission electron microscopy shows Sb delta-doped layers. Using standard photolithographic techniques, a 0.3 mm 2 Au Schottky contact...
Abstract Details of silicon diodes with Ge/Si multilayer quantum dot heterostructures embedded in the Si p–n junction grown by molecular beam epitaxy emitting range 1.4–1.7 µm at room temperature and continuous injection pumping are discussed. Output power light diode reaches 1 µW/cm 2 applied current density A/cm . Photoluminescence transmission electron microscopy show that origin intense luminescence is defect free stacked Ge array formed inside structure. It shown doping antimony...