Efeito da modulação da topologia do confinamento em sistemas quase zero-dimensionais induzida por campo elétrico

• Ano de defesa: 2015
• Autor(a) principal: Oliveira, Edson Rafael Cardozo de
• Orientador(a): Teodoro, Marcio Daldin
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Carlos
• Programa de Pós-Graduação: Programa de Pós-Graduação em Física - PPGF
• País: BR
• Palavras-chave em Português: Física da matéria condensada; Aharonov-Bohm, Teoria de; Pontos quânticos; InAs/GaAsSb
• Palavras-chave em Inglês: Aharonov-Bohm effect; Quantum dots
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://repositorio.ufscar.br/handle/ufscar/5078

Quantum dots grown by epitaxial techniques for optical and transport studies are usually capped by a layer of the same material on which the QDs were grown. Recently, several studies have shown how the growth parameters and materials used in this layer significantly affect the morphological, optical and electrical properties of these nanostructures. In this work Indium Arsenide quantum dots capped with a layer of Gallium Arsenide and Antimony are studied. After the growth, a rapid thermal annealing was performed, which improved significantly the size distribution of the quantum dots, increasing the optical eficiency, and inducing a change in the band structure from a Type-I to Type-II. The investigations performed by magnetophotoluminescence have shown that the effects of the topology confinement on the band structure of these quasi zero-dimensional systems are strongly modulated by an external electric field applied parallel to the magnetic field orientation. Purely quantum effects such as Aharonov-Bohm interference and the inversion of the excitonic Landfie g-factor were observed at low temperatures and for specific values of electric fields, showing that the choice of the material and growth conditions of quantum dots capping layer leads to controlled experimental results which could not be achieved using conventional growth methods of semiconductor quantum dots.