The many aspects of quantum dots

doi:10.1038/nnano.2010.127

Cited by 8 publications

(1 citation statement)

References 11 publications

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“…Mesoscopic semiconductor structures embody an extensive array of research with applications in electronic and optoelectronic devices and in the physical sciences. 1 Research into mesoscopic structures is an active field focused on fundamental physics at the nanoscale through the study of phenomena such as the Kondo effect, Andreev reflections, and spin qubits (for a concise review of these topics, see Ref. 2).…”

Section: Introductionmentioning

confidence: 99%

Electronic structure study of ion-implanted Si quantum dots in a SiO2matrix: Analysis of quantum confinement theories

2011

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The electronic states and optical properties of Si quantum dots (QDs) with variable size prepared by ion implantation in a SiO 2 matrix are studied by x-ray photoemission spectroscopy (XPS), photoluminescence (PL), and Raman spectroscopy. The results are compared with several theories of quantum confinement. Our Si 2p binding energies and the valence band energies do not change as a function of QD diameter nor compared to the bulk Si values. Raman spectra show no signs of stress on the Si-QDs. XPS data indicates the presence of a Si 2 O 3 interfacial layer between the Si-QDs and the surrounding SiO 2 matrix, which is understood to relieve stress in the QDs and to cause pinning of the valence level. Our XPS results for ion-beam implanted QDs are compared with other group's studies for Si-QDs prepared by alternative methods, and discrepancies in the interfacial compositions are discussed. These results call into question the fundamental predictions and assumptions of many quantum confinement models. It is concluded that the lack of a shift in the valence band is due to a symmetry-breaking process in the hole states, which is not currently accounted for by theory, demonstrating the importance of the hole states during radiative events. This work is intended as a first step in highlighting the features that should be present in a theoretical formalism for embedded Si-QDs, and cause is given to abandon particular formalisms.

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Section: Introductionmentioning

confidence: 99%

Electronic structure study of ion-implanted Si quantum dots in a SiO2matrix: Analysis of quantum confinement theories

2011

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Historical Perspective on Nanoparticles in Imaging from 1895 to 2000

Berezin

2014

Nanotechnology for Biomedical Imaging and Diagnostics

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Quantum Dots as Biophotonics Tools

César

2014

Quantum Dots: Applications in Biology

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This chapter provides a short review of quantum dots (QDs) physics, applications, and perspectives. The main advantage of QDs over bulk semiconductors is the fact that the size became a control parameter to tailor the optical properties of new materials. Size changes the confinement energy which alters the optical properties of the material, such as absorption, refractive index, and emission bands. Therefore, by using QDs one can make several kinds of optical devices. One of these devices transforms electrons into photons to apply them as active optical components in illumination and displays. Other devices enable the transformation of photons into electrons to produce QDs solar cells or photodetectors. At the biomedical interface, the application of QDs, which is the most important aspect in this book, is based on fluorescence, which essentially transforms photons into photons of different wavelengths. This chapter introduces important parameters for QDs' biophotonic applications such as photostability, excitation and emission profiles, and quantum efficiency. We also present the perspectives for the use of QDs in fluorescence lifetime imaging (FLIM) and Förster resonance energy transfer (FRET), so useful in modern microscopy, and how to take advantage of the usually unwanted blinking effect to perform super-resolution microscopy.

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The many aspects of quantum dots

Cited by 8 publications

References 11 publications

Electronic structure study of ion-implanted Si quantum dots in a SiO2matrix: Analysis of quantum confinement theories

Electronic structure study of ion-implanted Si quantum dots in a SiO2matrix: Analysis of quantum confinement theories

Historical Perspective on Nanoparticles in Imaging from 1895 to 2000

Quantum Dots as Biophotonics Tools

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