Quantum Dot
Mostrando 1-12 de 72 artigos, teses e dissertações.
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1. Review of Power Device for Solar-Powered Aircraft Applications
ABSTRACT This paper reviews various power device components of solar-powered aircraft such as photovoltaic (PV) cells, maximum power point tracker (MPPT) and rechargeable batteries. The various power device components were highlighted, and the ones applicable to aircraft were analyzed, based on criteria as efficiency for photovoltaic cells; energy densities
J. Aerosp. Technol. Manag.. Publicado em: 10/10/2019
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2. CÉLULAS SOLARES SENSIBILIZADAS POR PONTOS QUÂNTICOS
Quantum dot solar cells (QDSC) have been subject of extensive research in recent years. QDSC, as a promising alternative to existing solar cells, are among the candidates for next-generation photovoltaic devices that require low cost, high efficiency, so that quantum dots stand out for their unique features and versatile desirable on photovoltaic systems. Th
Quím. Nova. Publicado em: 2017-05
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3. Novel and Fast Microwave-Assisted Synthesis of Carbon Quantum Dots from Raw Cashew Gum
Carbon quantum dots (C-dots) with average size of 9 nm were synthesized from an aqueous solution of raw cashew gum (RCG) using a novel and fast microwave-assisted technique which involves two steps. In the first step (partial depolymerization in solution) some monomer units are formed through the autohydrolysis of CG and a small amount of 5-hydroxymethyl fur
J. Braz. Chem. Soc.. Publicado em: 2015-06
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4. Rate-equations based model for the 2D-0D direct channel in quantum dot lasers under CW and gain-switching
Direct capture of carriers from the wetting layer to the most confined states is discussed in this paper. This channel for carrier scattering was recently used to fit typical P-I curves of quantum dot lasers. Here new numerical expressions for the escape times accounting for the carriers added by the direct channel are introduced and evaluated, and insights
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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5. Efeito de interface nas propriedades ópticas de pontos quânticos de InP/GaAs / Interface effect on the optical properties of InP/GaAs quantum dots
We studied the effect of different interface conditions on the optical properties of InP/GaAs self-assembled quantum dots grown by chemical beam epitaxy in the Stranskii-Krastanov mode. InP/GaAs quantum dots is expected to present type II band alignment, and only electrons are confined, whereas the holes are localized in the GaAs layers around the quantum do
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/08/2012
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6. Controle de Corrente de Spin em Pontos Quânticos na Presença de Tensões de Porta Moduladas no Tempo
Since Loss &DiVincenzo proposal to use confined electron spins in quantum dots (QDs) as a building block for qubits in solid state systems, spin-dependent transport in QDs has attracted a lot of attention. The interest for this system increased even further with the recent experimental developments to coherently control (initialization-manipulation-read out)
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/08/2011
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7. 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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8. A study on the physical properties of quantum dot structures for infrared photodetection
Esta tese faz parte de uma proposta mais ampla cujo objetivo global e dominar a tecnologia de fotodetectores de radiacao infravermelha baseados em pontos quanticos semicondutores auto-organizados, os Quantum Dot Infrared Photodetectors (QDIPs), para a faixa de comprimento de onda de 2 a 20 Êm. A tese esta centrada no estudo das propriedades fisicas de ponto
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/07/2011
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9. Desenvolvimento, caracterizacao e aplicacao da matriz FTO/POLI(3-aminofenol) na deteccao de marcador de lesao cardiaca por fotoluminescencia de quantum dots
The heart is a vital organ propelling blood, that carries oxygen and nutrients throughout the body, but whenever these components do not reach it due to arterial obstruction, there is an electrical instability in the process of contraction of the muscle, causing arrhythmias that often, in less than an hour, causes acute myocardial infarction. The problem and
Publicado em: 2011
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10. Propriedades eletrÃnicas de pontos quÃnticos contendo muitos elÃtrons. / Electronic Properties of Quantum Dots Containing Many Electrons
Este trabalho dedica-se ao estudo das propriedades eletrÃnicas de pontos quÃnticos semicondutores contendo muitos elÃtrons confinados. Em particular, serÃo investigados semicondutores contendo muitos elÃtrons confinados. Em particular, serÃo investigados pontos quÃnticos de Si e Ge imersos em matrizes dielÃtricas (SiO2 e HfO2). O mÃtodo teÃrico uti
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 23/02/2010
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11. Polarização de spin em heteroestruturas semicondutoras contendo pontos quânticos de InAs
In this work, we have studied spin polarization of carriers in a resonant tunneling diode GaAs/AlGaAs with InAs quantum dots in the center of the quantum well. We have observed that the photoluminescence of quantum dots depends on applied voltage and light intensity. Our results were explained by the capture of minority carriers (holes) to quantum dot energy
Publicado em: 2010
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12. Fotorefletância em pontos quânticos auto-organizados de InAs crescidos sobre GaAs e no interior de um poço quântico de In0.14Ga0.86As/GaAs
Neste trabalho estudamos pontos quânticos QDs (quantum dots) de InAs auto-organizados crescidos sobre o GaAs, formando uma estrutura convencional de quantum dots, e crescidos no interior de um poço quântico de In0.14Ga0.86As/GaAs, formando uma estrutura denominada DWELL (dot-in-a-well). Utilizamos cinco amostras de QDs de InAs crescidas através da té
Publicado em: 2010