A5016963652- Silicon Nanostructures and Photoluminescence
- Quantum Dots Synthesis And Properties
- Nanowire Synthesis and Applications
- ZnO doping and properties
- Semiconductor Quantum Structures and Devices
- Semiconductor materials and devices
- Advanced Semiconductor Detectors and Materials
- Semiconductor Lasers and Optical Devices
- Ga2O3 and related materials
- Copper-based nanomaterials and applications
- Chalcogenide Semiconductor Thin Films
- Gas Sensing Nanomaterials and Sensors
- Thin-Film Transistor Technologies
- Advanced biosensing and bioanalysis techniques
- Semiconductor materials and interfaces
- Silicon Carbide Semiconductor Technologies
- Advanced Biosensing Techniques and Applications
- Ion-surface interactions and analysis
- Integrated Circuits and Semiconductor Failure Analysis
- Carbon Nanotubes in Composites
- Electronic and Structural Properties of Oxides
- Boron and Carbon Nanomaterials Research
- Advanced ceramic materials synthesis
- solar cell performance optimization
- Diamond and Carbon-based Materials Research
Instituto Politécnico Nacional
2015-2024
V.E. Lashkaryov Institute of Semiconductor Physics
2019-2020
Tecnológico Nacional de México
2006-2015
Polytechnic University of Puerto Rico
2005-2007
National Academy of Sciences of Ukraine
2002
Photoluminescence, its temperature dependence, and photoluminescence excitation spectra of InAs quantum dots embedded in asymmetric InxGa1−xAs∕GaAs wells [dots a well (DWELL)] have been investigated as function the indium content x (x=0.10–0.25) capping InxGa1−xAs layer. The DWELL structures were created with aim to investigate influence different barrier values at dot (QD)/quantum interface on thermal quenching process. set rate equations for two stage model capture escape excitons QDs are...
The temperature-dependent photoluminescence (PL) spectra of highly uniform self-assembled InAs quantum dots (QDs) embedded in In0.15Ga0.8As/GaAs multi-quantum well (MQW) structures have been investigated. Spectral peak shift and PL temperature quenching for ground state (GS) first excited (1ES) optical transitions the range 12–220 K are analyzed. Small FWHM values equal to 37 27 meV at 12 characterize GS 1ES transitions, respectively. For QDs no unusual decrease low temperatures was seen...
Photoluminescence (PL), its temperature and excitation power dependences, PL spectra have been investigated in InAs quantum dots (QDs) embedded In0.15Ga0.85As/GaAs wells (QWs) as a function of QD density. The density varied from 1.1×1011 down to 1.3×1010 cm−2 with the increase growth at molecular beam epitaxy processing. A set rate equations for exciton dynamics (relaxation into QWs QDs, thermal escape) has solved analyze mechanism quenching studied structures. Three stages revealed decay...
Spatially-resolved photoluminescence (PL) spectroscopy was performed at different temperatures on self-assembled InAs quantum dots embedded into MBE-grown In0.15Ga0.85As∕GaAs multiquantum-well heterostructures. Strong inhomogeneity of the PL intensity is observed by mapping samples with In∕Ga composition InxGa1−xAs capping layers (0.1⩽x⩽0.2). Two behaviors in quantum-dot maps are observed: (1) a reduction accompanied gradual “blue” shift luminescence maximum 300K and “red” 80K, (2) variation...
The paper presents the results of photoluminescence (PL) and Raman scattering studies non-conjugated bio-conjugated CdSe/ZnS core-shell quantum dots (QDs). commercial QDs used are characterized by color emission with maxima at 605-610 nm (2.03-2.05 eV). PL spectra superposition bands related to exciton in CdSe core eV) hot electron-hole via defect states interface (2.37 2.68 QD conjugation was performed biomolecules -- antihuman interleukin 10 antibody (antihuman IL10). have been changed...
This paper presents a temperature-dependent scanning photoluminescence spectroscopic study of the ground and excited states on InAs quantum dots (QDs) inserted into ${\mathrm{In}}_{0.15}{\mathrm{Ga}}_{0.85}\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ wells. It is shown that structures exhibit long-range spatial variation QD electronic across wafer. The observed trend state energy attributed to size applied explore multiple shift versus energy. Experimental results are compared with level dependence...
Abstract This paper presents the results of peculiarity analysis in PL spectra CdSe/ZnS QDs different sizes. Commercially available core/shell characterized by emission at 525 nm (2.36 eV), 560 (2.22 605 (2.05 eV) and 640 (1.94 have been studied. were measured excitation a He‐Cd laser with light wavelength 325 temperatures 10 300K. size can be presented as superposition 3 elementary bands: (i) band deals ground state exciton CdSe core (ii) two bands (2.37 2.68 assigned to electron‐hole...
The photoluminescence (PL), its temperature and power dependences, as well PL inhomogeneity x ray diffraction (XRD) has been studied in the symmetric In0.15Ga1−0.15As/GaAs quantum wells with embedded InAs dots (QDs) (dot-in-a-well, DWELL) different QD densities, obtained by variation growth temperatures. It is shown that four reasons are responsible for difference emission intensities, peak positions structures: (i) high concentration of nonradiative (NR) recombination centers capping...
The excitation, emission, electron paramagnetic resonance, and Raman scattering spectra of as-prepared aged Si wires, like porous silicon, have been examined. Atomic force microscope is used for the surface morphology investigation, as well study this connection with photoluminescence (PL) peculiarities. Two elementary PL bands in red orange spectral ranges: $h{\ensuremath{\nu}}_{m}=1.70--1.73$ 1.80--2.00 eV, observed. It shown ballistic effect can enhance very effective hot carrier...
The optical characteristics (transmission and reflection, absorption scattering coefficients) of the Si nanowires obtained by electrochemical treatment wafers were studied experimentally in spectral range 350–750 nm, using different angles incidence measuring angular distribution reflected (scattered) light. Theoretical made on basis Mie theory some original modelling explains determined gives a simple method estimation refractive index porous semiconductor layer created above bulk specimen....
Abstract Core‐shell CdSe/ZnS quantum dots are promising as bio‐luminescent markers: being conjugated to bio molecules (proteins), they serve luminescence tags in antigen‐antibody biochemical reaction. This presents a possibility detect, for example, the variation of protein biomarkers promote early cancer diagnosis. We studied effect QDs using Raman scattering spectra, and found that some cases conjugation leads noticeable these so detection could be done more accurately. An explanation is...