Quantum Confinement
Mostrando 1-12 de 58 artigos, teses e dissertações.
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1. NANOCRISTAIS DE PEROVSKITAS COLOIDAIS: HISTÓRICO, PROPRIEDADES E APLICAÇÕES
Recently, a new class of materials, the Perovskite Nanocrystals, also known as perovskite quantum dots (PQDs) has emerged. Perovskite nanocrystals are promising in optoelectronics due to their quantum confinement properties, narrow photoluminescence bands with short decay times, optically tunable bandgaps, easy surface passivation and high photoluminescent q
Quím. Nova. Publicado em: 2020-09
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2. Characterization of CBD-CdS Doped with Some Rare Earths III (Eu3+,Ce3+) as Function of Synthesis Time
Rare earths (Europium, cerium)-doped CdS nanofilms are prepared using the growth technique chemical bath deposition (CBD) at the reservoir temperature of 70±2°C varying the synthesis time in a wide range. For the rare earths doped CdS nanofilms the synthesis time was ranged from 80 to 135 min. The rare earths molar concentration was in the range 0.0≤x≤
Mat. Res.. Publicado em: 01/02/2018
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3. PONTOS QUÂNTICOS AMBIENTALMENTE AMIGÁVEIS: DESTAQUE PARA O ÓXIDO DE ZINCO
Semiconductor nanocrystals with sizes in the quantum confinement regime (2-10 nm) present special physical and chemical properties. Additionally, environment-friendly quantum dots (QDs), as zinc oxide and zinc sulfide, offer many practical usages. Herein the ZnO semiconductor nanocrystals properties will be preferentially explored, such as its luminescence,
Quím. Nova. Publicado em: 2017-10
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4. Temperature and Deposition Time Effect on Properties and Kinetics of CdSe and CdS0.25Se0.75 Films Deposited by CBD
CdSe and CdS0.25Se0.75 thin films were grown by the Chemical Bath Deposition technique at different temperatures (50-90°C) and deposition times (5-180 min). Both kinds of films are polycrystalline, constituted by nanostructured clusters of particles. CdSe films consist in a mixture of cubic and hexagonal phases (4-8 nm crystal size), whereas only the hexago
Mat. Res.. Publicado em: 26/06/2017
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5. Structural, Optical, Morphological and Dielectric Properties of Cerium Oxide Nanoparticles
Cerium oxide (CeO2) nanoparticles were prepared by the precipitation method. The average crystallite size of cerium oxide nanoparticles was calculated from the X-ray diffraction (XRD) pattern and found to be 11 nm. The FT-IR spectrum clearly indicated the strong presence of cerium oxide nanoparticles. Raman spectrum confirmed the cubic nature of the cerium o
Mat. Res.. Publicado em: 15/03/2016
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6. Lattice QCD: a nonperturbative study in the Feynman Gauge / QCD na rede: um estudo não-perturbativo no calibre de Feynman
The infrared behavior of gluon and ghost propagators is of fundamental importance for the understanding of the low-energy limit of quantum chromodynamics (QCD), especially with respect to the problem of the confinement of quarks and gluons. The goal of this thesis is to implement a new method to study the gluon propagator in the linear covariant gauge in lat
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/08/2011
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7. FIRST PRINCIPLES STUDY OF INDIUM ARSENIDE AND INDIUM PHOSPHIDE NANOWIRES / ESTUDO DE PRIMEIROS PRINCÍPIOS DE NANOFIOS EM ARSENETO DE ÍNDIO E FOSFETO DE ÍNDIO
Neste trabalho realizamos um estudo teórico, baseado na teoria do funcional da densidade, em nanofios de InAs e InP e em heteroestruturas de nanofios InAs/InP. Inicialmente estudamos a variação das propriedades estruturais, eletrônicas e mecânicas com o diâmetro em nanofios de InAs e InP, e as possíveis alterações nas propriedades eletrônicas deste
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/07/2011
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8. Efeito capacitivo em um sistema de dois pontos quânticos acoplados no regime Kondo
In this work we study a system composed by two quantum dots coupled to each other and one of each coupled to two metallic leads. Theoretically the system is described by a generalized two-impurity Anderson model. In this Hamiltonian we include both intraand inter-site electron-electron interaction, where the former is due to the confinement of electrons in a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/07/2011
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9. Quantum confinement in PbI2 nanodisks prepared with cucurbit[7]uril
Este trabalho apresenta uma rota alternativa para a preparação de nanodiscos de iodeto de chumbo (ca. 50-340 × 7Å, diâmetro × espessura) utilizando o macrocíclico cucurbit[7]urila como molde de síntese e agente estabilizante. Estas nanopartículas apresentam um deslocamento para o azul de gap óptico consistente com seu tamanho reduzido e confinament
Journal of the Brazilian Chemical Society. Publicado em: 2011-08
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10. Estudo de pontos quânticos auto-organizados de InAs por fotoluminescência
Semiconductor structures with high confinement degree, such as quantum wells, quantum wires and quantum dots, have been of great interest, both from the technological point of view and for basic research. Self-Assembled Quantum Dots (SAQD`s) appear spontaneously, as a consequence of the lattice mismatch of the material deposited in relation to the substrate,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/02/2010
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11. Tuning luminescence of 3d transition- metal doped quantum particles: Ni+2: CdS and Fe+3: CdS
The room- temperature photoluminescence of Cd1- xMxS (M=Ni, Fe) nanoparticles were investigated. Compared with the photoluminescence of CdS which peaks at 475 nm, the photoemission of CdS:Fe nanoparticles was peaking at 537 nm because of Fe acting as luminescent centers. On the other hand, the green emission (503 nm) of CdS:Ni attributed to the ¹T2g(D)→ �
Brazilian Journal of Physics. Publicado em: 2010-09
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12. O estado da arte da síntese de semicondutores nanocristalinos coloidais
Colloidal semiconductor nanocrystals, also known as quantum dots, have attracted great attention since they have interesting size-dependent properties due to the quantum confinement effect. These nanoparticles are highly luminescent and have potential applications in different technological areas, including biological labeling, light-emitting diodes and phot
Química Nova. Publicado em: 2010