Semiconductor
Mostrando 1-12 de 440 artigos, teses e dissertações.
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1. Study of structural, optical, and morphological characteristics of manganese titanate (MnTiO3) obtained by combustion reaction using microwave energy
Abstract MnTiO3 is a semiconductor that has relevant dielectric and optical properties. For the synthesis of manganese titanate (MnTiO3) powders, the combustion method via microwave and subsequent calcination at 500, 700, and 900 °C were used. The structural, morphological, and optical properties of the samples were investigated. X-ray diffraction analyzes
Cerâmica. Publicado em: 2021-03
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2. High-Speed Pulse Sequences through Semiconductor Optical Nonlinear Amplification and Buried Fiber Propagation
Abstract Microwave pulse bursts were obtained through optical domain intensity modulated microwave carriers, sliced by cascaded modulator technique, followed by non-linear semiconductor optical amplifier (SOA) pre-chirp. After 3 to 18 km of buried fiber propagation and photo detection, the microwave signals presented increased extinction ratio, up to 36 GHz,
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-09
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3. SÍNTESE E CARACTERIZAÇÃO DE PONTOS QUÂNTICOS AMBIENTALMENTE AMIGÁVEIS, UM MEIO SIMPLES DE EXEMPLIFICAR E EXPLORAR ASPECTOS DA NANOCIÊNCIA E NANOTECNOLOGIA EM CURSOS DE GRADUAÇÃO
Nanotechnologies and nanomaterials are very current and interesting topics and can be used as interdisciplinary tools in education. They can be used to work in a practical and interesting way with lots of subjects. In chemistry teaching it can be particularly important to consolidate the nanomaterials, nanotechnology and characterization teaching. Among the
Quím. Nova. Publicado em: 2020-06
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4. CONVERSÃO FOTOELETROCATALÍTICA DE CO2 E BIOGÁS EM PRODUTOS DE INTERESSE ENERGÉTICO UTILIZANDO SEMICONDUTORES NANOESTRUTURADOS DE Ti/TiO2 MODIFICADOS COM ÓXIDO DE COBRE
This work describes the superficial modification of Ti/TiO2 nanotubes by copper oxide electrochemical deposition, in different temperatures (25 and 65 ºC), and its application on the photoelectrocatalytic conversion of CO2 and biogas in products of energy interest. The different temperatures deposition resulted in the formation of different geometric forms
Quím. Nova. Publicado em: 2020-02
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5. An Overview of the Photocatalytic H2 Evolution by Semiconductor-Based Materials for Nonspecialists
The solar-to-chemical energy conversion is promising to tackle sustainability challenges toward a global future. The production of H2 from sunlight represents an attractive alternative to the use of carboniferous fossil fuels to meet our energy demands. In this context, the water splitting reaction photocatalyzed by semiconductors that can be excited under v
J. Braz. Chem. Soc.. Publicado em: 2020-02
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6. TiO2 Decorated Sand Grains for Photodegradation of Pollutants: Methylene Blue and Ciprofloxacin Study
This study shows a preparation and evaluation of a new non-expensive TiO2 based photocatalyst built over sand grains surfaces as an alternative green technology for water treatment. The semiconductor covalently bonded to the silica sand grains (sand@TiO2) prepared by hydrolysis of isopropoxide orthotitane over sand grains, showed a high surface area 296 m2 g
J. Braz. Chem. Soc.. Publicado em: 2020-01
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7. Dendritic Gold Nanoparticles Towards Transparent and Electroactive Electrodes
Abstract: The combination of UV-visible absorption and electrochemical experiments (spectroelectrochemistry) enables to obtain highly specific spectroscopic information (in situ and operando) from modified surfaces. However, such application can be limited by the self-absorbance, for example, when metallic nanoparticles are present on modified surfaces. Indi
An. Acad. Bras. Ciênc.. Publicado em: 28/11/2019
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8. Effect of High-pressure Torsion on Corrosion Behavior of a Solution-treated Al-Mg-Sc Alloy in a Saline Solution
The effect of the increase in crystalline defects in the structure generated by high-pressure torsion (HPT) on the corrosion behavior of metallic materials is not well understood. This report evaluates the influence of HPT on the corrosion behavior of a solution treated Al-3wt% Mg-0.2wt% Sc alloy in a 3.5 wt./v.% NaCl solution. The electrochemical behavior o
Mat. Res.. Publicado em: 04/11/2019
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9. (Bio)conjugation Strategies Applied to Fluorescent Semiconductor Quantum Dots
Quantum dots (QDs) are semiconductor nanocrystals, which present unique photophysical properties, enabling their application as new fluorescent platforms for biomedical sciences. Colloidal QDs are end-capped with organic or inorganic compounds, not only to prevent their agglomeration but also to provide reaction sites for the attachment of targeting (bio)mol
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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10. Green synthesis and Characterization of ZnO-CoFe2O4 Semiconductor Photocatalysts Prepared Using Rambutan (Nephelium lappaceum L.) Peel Extract
In this work, the semiconductor of ZnO-CoFe2O4 composites were prepared by green synthesis approach using rambutan peel extract (Nephelium lappaceum L.) as a capping agent. X-ray diffraction patterns of composites showed the main peaks of ZnO at 2θ = 31.8°, 34.5°, and 36.2° corresponding to hexagonal wurtzite structure and weak peak at 2θ = 35.4° for c
Mat. Res.. Publicado em: 30/09/2019
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11. Estudo das propriedades do Diodo Emissor de Luz (LED) para a determinação da constante de Planck numa maquete automatizada com o auxílio da plataforma Arduíno
Resumo No presente artigo, apresenta-se o método experimental de determinação da constante de Planck, uma das constantes físicas fundamentais, através do estudo das propriedades quânticas e ondulatórias do diodo emissor de luz (LED) numa maquete experimental automatizada, que contém um circuito eletrônico ligado a um computador utilizando o protocol
Rev. Bras. Ensino Fís.. Publicado em: 09/09/2019
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12. Study of the Nb2O5 Insertion in ZnO to Dye-sensitized Solar Cells
Dye-sensitized solar cells (DSSC) have received much attention as an alternative to silicon-based solar cells, due to various advantages. Zinc oxide (ZnO) is an n-type semiconductor employed as photoanode on DSSC. The decrease of charge recombination is an efficient strategy capable of improving the photovoltaic performance of the device. In this perspective
Mat. Res.. Publicado em: 01/07/2019