A5055725274- Semiconductor Quantum Structures and Devices
- Advanced Semiconductor Detectors and Materials
- Semiconductor materials and devices
- Biofuel production and bioconversion
- Chalcogenide Semiconductor Thin Films
- Electronic and Structural Properties of Oxides
- Enzyme Production and Characterization
- Quantum and electron transport phenomena
- Quantum Dots Synthesis And Properties
- Sugarcane Cultivation and Processing
- Nanowire Synthesis and Applications
- Catalysis for Biomass Conversion
- Advanced Cellulose Research Studies
- Topological Materials and Phenomena
- Spectroscopy and Laser Applications
- Advanced Sensor and Energy Harvesting Materials
- Advancements in Semiconductor Devices and Circuit Design
- Advanced Materials and Mechanics
- 2D Materials and Applications
- Adhesion, Friction, and Surface Interactions
- Graphene research and applications
- Physics of Superconductivity and Magnetism
Universidade Federal de Viçosa
2019-2023
Laboratório Nacional de Ciência e Tecnologia do Bioetanol
2019-2021
Brazilian Center for Research in Energy and Materials
2021
Laboratório Nacional de Nanotecnologia
2019
Pontifícia Universidade Católica de Campinas
2019
Universidade Federal de Juiz de Fora
2013-2016
Heavy usage of gasoline, burgeoning fuel prices, and environmental issues have paved the way for exploration cellulosic ethanol. Cellulosic ethanol production technologies are emerging require continued technological advancements. One most challenging is pretreatment lignocellulosic biomass desired sugars yields after enzymatic hydrolysis. We hypothesized that consecutive dilute sulfuric acid-dilute sodium hydroxide would overcome native recalcitrance sugarcane bagasse (SB) by enhancing...
Diminishing supplies of fossil fuels and oil spills are rousing to explore the alternative sources energy that can be produced from non-food/feed-based substrates. Due its abundance, sugarcane bagasse (SB) could a model substrate for second-generation biofuel cellulosic ethanol. However, efficient bioconversion SB remains challenge commercial production We hypothesized oxalic-acid-mediated thermochemical pretreatment (OAFEX) would overcome native recalcitrance by enhancing cellulase...
Abstract We report the role of bandgap energy in Cd 1−x Mn x Te thin films photoinduced crystallization tellurium under prolonged exposure to visible light. Raman spectroscopy was used quantify evolution trigonal phase ( t -Te) over time. Our results reveal that when incident photons exceeds energy, photocrystallization process seems be controlled by diffusion and consistent with growth one-dimensional forming crystalline structures. Conversely, excitation is lower than effect completely...
MnBi2Te4 is one of the most recent materials that integrates class topological quantum exhibiting insulating properties and magnetic ordering, thus providing opportunity to investigate particular states design novel spintronic devices. The samples were grown on GaAs(100) substrates using molecular beam epitaxy with Bi2Te3, Te Mn as sources. growth was characterized through X-ray diffraction, atomic force microscopy transmission electron microscopy. Topological insulator probed scanning...
The control of the magnetic properties shapeable devices and manipulation flexible structures by external fields is a keystone future magnetoelectronics-based devices. This work studies elastic magnetoelastic nanodisc that hosts meron as state can be deformed from with positive to negative Gaussian curvature. We show winding number hosted crucial determine curvature sign stable obtained shape. Additionally, we optimum reached depends on geometrical mechanical parameters. It shown an increase...
Strain-based band structure engineering is a powerful tool to tune the optical and electronic properties of semiconductor nanostructures. We show that we can InGaAs quantum wells modify helicity emitted light by integrating them into rolled-up heterostructures changing their geometrical configuration. Experimental results from photoluminescence excitation spectroscopy demonstrate strong energy shift valence-band states in comparison flat structures, as consequence an inversion heavy-hole...
Overcoming the critical thickness limit in pseudomorphic growth of lattice mismatched heterostructures is a fundamental challenge heteroepitaxy.
Abstract This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were by molecular beam epitaxy and characterized scanning transmission electron microscopy, macro- micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three bands which depend the CdTe layer thickness different confinement characteristics....
In this paper we investigate the resonant intersubband Raman scattering of two-dimensional electron systems in GaAs-AlGaAs single quantum wells. Self-consistent calculations polarized and depolarized cross sections show that appearance excitations at unrenormalized single-particle energy are related to three factors: extreme resonance regime, existence degeneracy gas, and, finally, interactions between pairs excitations. It is demonstrated physics governs problem similar one gives rise...
Ultra-thin layers (<8 nm) of a Bi2Te3 topological insulator have been grown on GaAs (100) substrates using molecular beam epitaxy. The growth was performed from single effusion cell and one source extra tellurium. Optical structural characterizations were carried out through Raman spectroscopy, x-ray diffraction, atomic force microscopy, scanning electron microscopy. properties also investigated by angle-resolved photoelectron spectroscopy. A layer 5 nm showed Dirac cone-like linear...
We investigate the optical properties of strain-free mesoscopic GaAs/Al x Ga1 - As structures (MGS) coupled to thin quantum wells (QWs) with varying Al content (x). demonstrate that quenching QW emission by controlling band crossover between AlGaAs (X-point) and GaAs (Γ-point) gives rise long carrier lifetimes enhanced from MGS. For = 0.33, MGS show typical type-I alignment strong photoluminescence much weaker sharp recombination lines localized exciton states. ≥ 0.50, is considerably...
Cd1−xMnxTe (CMT) is a wide bandgap semiconductor that stands out among the ternary compounds in several industrial applications, such as optoelectronic and solar cell devices. Therefore, it worth understanding mechanisms of light interaction with CMT produced by growth techniques. In this work, we investigate room temperature Raman scattering longitudinal optical phonon modes CdTe-like (LO1) MnTe-like (LO2) thin films grown on Si(111) molecular-beam epitaxy. The well-known linear dependence...