Propriedades eletrônicas de pontos quânticos de InAs1-xPx sobre GaAs. / Electronic Properties of InAs1-xPx quantum dots on GaAs.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The growth of quantum dots in the Stranski-Krastranov mode has been subject of intense investigation in the last decade. Knowing the electronics properties of these materials is key for performing quantum systems engineering. The objective of this work is to study the quantum dots (QD) electronic properties of the InAS1-x Px embedded in GaAs. The study was done by capacitance spectroscopy (CV), which is an experimental tool that allows the evaluation of the electronic states and the charge distribution of a given quantum device. The samples of InAS1-x Px were grown by Low-Pressure Metalorganic Chemical Vapor Deposition on GaAs:Cr (001) substrates. They consist of metalinsulator-semiconductor structures with an n-type back contact. The measurements were performed at 4.2 K for different values of frequencies and magnetic field. From the confined states dispersion as a function of the applied magnetic field, perpendicular to the QD plane, the system natural frequency, ◚, was determined. From the ◚, we could determine the wave function characteristic length, 𕖮. The concordance between the 𕖮, values and the lateral sizes obtained by Transmission Electronic Microscopy (TEM) is good. Finally, by CV spectroscopy we could separate the lateral and vertical confinement effects, leading to a more complete understanding of the Photoluminescence (PL) spectra, as well as the details of the QD shape obtained by TEM.

ASSUNTO(S)

inp inasp pontos quânticos capacitance spectroscopy inp inasp electroscopia de capacitância gaas gaas quantum dots

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