A5042022525- GaN-based semiconductor devices and materials
- Metal and Thin Film Mechanics
- Semiconductor materials and devices
- Semiconductor Quantum Structures and Devices
- Ga2O3 and related materials
- ZnO doping and properties
- Nanowire Synthesis and Applications
- Silicon Nanostructures and Photoluminescence
- Plasma Diagnostics and Applications
- Thin-Film Transistor Technologies
- Semiconductor materials and interfaces
- Plasmonic and Surface Plasmon Research
- Adenosine and Purinergic Signaling
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Silicon Carbide Semiconductor Technologies
- Silicon and Solar Cell Technologies
- Optical Coatings and Gratings
- Pancreatic function and diabetes
- Near-Field Optical Microscopy
- Photonic and Optical Devices
- Electron and X-Ray Spectroscopy Techniques
- Photocathodes and Microchannel Plates
- Anodic Oxide Films and Nanostructures
- Neonatal Health and Biochemistry
Institute of High Pressure Physics
2010-2024
Polish Academy of Sciences
2007-2023
TopGaN (Poland)
2021
Maria Curie-Skłodowska University
1979-2004
Asur Plant Breeding (France)
2002
Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications
2002
Centre National de la Recherche Scientifique
2002
Boston University
2002
University of New Mexico
2002
Linköping University
1997
We have analyzed red and blue luminescence from porous silicon as a function of oxidation parameters feature dimension determined with an atomic force microscope. found correlation between intensity the increase in size caused by oxidation. further shown that luminescence, is identical, respect to spectrum fast decay, high microelectronic quality SiO2 grown on crystalline using dry oxygen plus organic chlorine compound. Thus, we conclude originates film rather than nanocrystals material....
Crystallization of GaN by hydride vapor phase epitaxy (HVPE) on ammonothermally grown seed crystals is described. The initial growth conditions for HVPE are determined and applied further bulk growth. Smooth layers up to 1.1 mm thick excellent crystalline quality, without cracks, with low dislocation density obtained. Preparation the free-standing HVPE-GaN crystal slicing structural optical quality resulting wafer presented.
Homoepitaxial, GaN films on both c-plane surfaces of bulk crystals were examined using reflection high-energy electron diffraction (RHEED). Differences in the RHEED pattern, time development intensity, and surface reconstructions observed. The substrate prepared either by mechanical polishing [GaN(0001)A] or chemo-mechanically [GaN(0001̄)B]. Then grown molecular beam epitaxy; Ga was provide a Knudsen cell nitrogen from NH3. On B surface, rich reported Smith co-workers [Phys. Rev. Lett. 79,...
The results on growth and magnetotransport characterization of AlGaN∕GaN heterostructures obtained by plasma assisted molecular beam epitaxy dislocation-free (below 100cm−2) GaN high pressure synthesized bulk substrates are presented. record mobilities the two dimensional electron gas (2DEG) exceeding 100000cm2∕Vs at liquid helium temperature 2500cm2∕Vs room reported. An analysis field conductivity tensor components allowed us to discuss main scattering mechanisms confirm unambiguously 2DEG...
Surface polarity plays a significant role in chemical etching of GaN KOH solution, process that is important for quality control and device fabrication. In this work, basic mechanisms are proposed to explain the surface orientation semiconductor. addition, it shown how prior photoetching inert surfaces [the polar (0001), semipolar (101̅1̅), nonpolar (11̅00) interfaces] enables etching. Photoetching gives rise formation nanocolumns on dislocations protrusions nanoscale inhomogeneities....
We demonstrate continuous-wave operation at 411nm of InGaN multi-quantum-well laser diodes (LDs) made by plasma-assisted molecular-beam epitaxy (PAMBE). The threshold current density and voltage for these LDs are 4.2kA∕cm2 5.3V, respectively. High optical output power 60mW is achieved. fabricated on low-dislocation-density bulk GaN substrates, growth conditions which resemble liquid-phase epitaxy. show that use such substrates eliminates spiral growth, the dominant mechanism PAMBE...
Epitaxial GaN films have been grown on single-crystal substrates, using surface cracked ammonia as nitrogen precursor for molecular beam epitaxy. With this approach excellent optical and structural properties are achieved. Low-temperature photoluminescence shows well-resolved excitonic lines with record low linewidths narrow 0.5 meV. The transitions attributed to excitons bound neutral donors ((D°, X) 1 at 3.4709 eV (D°, 2 3.4718 eV) a acceptor ((A°, 3.4663 eV). In addition, free exciton...
We demonstrate that relatively small GaN substrate misorientation can strongly change hole carrier concentration in Mg doped layers grown by metalorganic vapor phase epitaxy. In this work intentionally misoriented substrates (up to 2° with respect ideal ⟨0001⟩ plane) were employed. An increase the level above 1018 cm−3 and a decrease GaN:Mg resistivity below 1 Ω cm achieved. Using secondary ion mass spectroscopy we found incorporation does not varying angle. This finding suggests...
Crystallization of GaN by hydride vapor phase epitaxy (HVPE) on ammonothermally grown seed crystals is overviewed. Morphology the crystal growing surface at beginning crystallization process and end it presented. Based these results a rough growth model proposed. Smooth layers up to 1 mm thick high purity, excellent crystalline quality, without any cracks, with low dislocation density are grown. Preparation free-standing HVPE-GaN slicing as well structural, electrical optical qualities...
We have found a new photoluminescence (PL) band with maximum at 0.9 eV and halfwidth of 0.1 4.2 K in polycrystalline Si thin films deposited on glass 625 °C. The PL strongly shifts toward low energy increasing the temperature (1.3 meV/K) high excitation intensity. Hydrogenation enhances intensity by factor 3 to 5. luminescence characteristics are consistent radiative recombination electrons holes trapped tail states conduction valence band, respectively. Excellent agreement is achieved...
Abstract We have studied the properties of InGaN layers and quantum wells grown on gallium nitride substrates with intentional surface misorientation respect to its crystalline c ‐axis. Misorientation varied in range from 0 up 2 degree. The indium content was changed by using different growth temperature (between 750 °C 820 °C) during metalorganic vapor phase epitaxy. With increasing angle average decreased significantly. This effect accompanied strong increase emission line bandwidth...
The impact of wet treatment using an (NH4)2S-alcohol solution on the interface state p-GaN/Ni/Au/Pt contact system and laser diode processing was investigated. Sulfur cleaning resulted in reduced surface roughness resistivity. lowest specific resistance (ρc < 1 × 10−4 Ω·cm2) achieved with samples treated (NH4)2S-isopropanol solution, whereas highest resistivity = 3.3 (Ra 16 nm) were observed prepared by standard methods. Annealing N2 + O2 H2O atmosphere caused degradation through species...
The fabrication procedure of efficient surface enhanced Raman scattering (SERS) platforms is demonstrated based on reproducibly photo-etched GaN epitaxial layers covered by a thin Au-Ag layer and subjected to partial de-alloying. Using gold-rich Au57Ag43 alloy (70/30 wt. %), it possible preserve about 19 at. % silver in the layer, even after etching nitric acid for up 24 h. A large enhancement signal from test 4-mercaptobenzoic molecules attached such porous metal obtained due presence high...
Abstract The presence of multiple intracellular and extracellular proteolytic activities in trophophasic (nutrientrich) idiophasic (carbon‐or nitrogen‐starved) cultures the white‐rot fungi Trametes versicolor Phlebia radiata was demonstrated by electrophoresis on polyacrylamide gels containing denatured haemoglobin as a substrate. In T. , seven electrophoretically distinguishable proteases were defined using mycelial extracts six (three clear three less intensive) secreted proteases. For P....