Optical emission from a charge-tunable quantum ring
R. J. Warburton,R. J. Warburton,C. Schäflein,D. Haft,F. Bickel,Axel Lorke,Khaled Karrai,Jorge M. Garcia,Winston V. Schoenfeld,Pierre Petroff +9 more
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TLDR
It is found that the emission energy changes abruptly whenever an electron is added to the artificial atom, and that the sizes of the jumps reveal a shell structure.Abstract:
Quantum dots or rings are artificial nanometre-sized clusters that confine electrons in all three directions. They can be fabricated in a semiconductor system by embedding an island of low-bandgap material in a sea of material with a higher bandgap. Quantum dots are often referred to as artificial atoms because, when filled sequentially with electrons, the charging energies are pronounced for particular electron numbers; this is analogous to Hund's rules in atomic physics. But semiconductors also have a valence band with strong optical transitions to the conduction band. These transitions are the basis for the application of quantum dots as laser emitters, storage devices and fluorescence markers. Here we report how the optical emission (photoluminescence) of a single quantum ring changes as electrons are added one-by-one. We find that the emission energy changes abruptly whenever an electron is added to the artificial atom, and that the sizes of the jumps reveal a shell structure.read more
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Engineering atomic and molecular nanostructures at surfaces
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Electrical control of neutral and charged excitons in a monolayer semiconductor
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Quantum Confined Stark Effect in Single CdSe Nanocrystallite Quantum Dots
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Broad-range modulation of light emission in two-dimensional semiconductors by molecular physisorption gating.
Sefaattin Tongay,Jian Zhou,Can Ataca,Jonathan Liu,Jeong Seuk Kang,Tyler S. Matthews,Long You,Jingbo Li,Jeffrey C. Grossman,Junqiao Wu,Junqiao Wu +10 more
TL;DR: Physi-sorbed O2 and/or H2O molecules electronically deplete n-type materials such as MoS2 and MoSe2, which weakens electrostatic screening that would otherwise destabilize excitons, leading to the drastic enhancement in photoluminescence.
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Self-tuned quantum dot gain in photonic crystal lasers.
Stefan Strauf,K. Hennessy,Matthew T. Rakher,Y.S. Choi,Antonio Badolato,Lucio Claudio Andreani,Evelyn Hu,Pierre Petroff,Dirk Bouwmeester +8 more
TL;DR: Photon correlation measurements show a transition from a thermal to a coherent light state proving that lasing action occurs at ultralow thresholds, and it is demonstrated that very few quantum dots as a gain medium are sufficient to realize a photonic-crystal laser based on a high-quality nanocavity.
References
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Semiconductor Nanocrystals as Fluorescent Biological Labels
TL;DR: Semiconductor nanocrystals prepared for use as fluorescent probes in biological staining and diagnostics have a narrow, tunable, symmetric emission spectrum and are photochemically stable.
Book
Quantum dot heterostructures
TL;DR: In this paper, the growth and structural characterisation of self-organized Quantum Dots are discussed. But they do not consider the model of ideal and real quantum Dots.
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Quantum Processes in Semiconductors
TL;DR: In this paper, the energy and momentum conservation of phonon-impurity coupling in the diamond lattice is discussed. But the authors do not consider the effect of photo-ionization on photo-deionization of a hydrogenic acceptor.
Journal ArticleDOI
Shell Filling and Spin Effects in a Few Electron Quantum Dot.
TL;DR: Coulomb oscillations in vertical quantum dots containing a tunable number of electrons starting from zero are measured, as predicted by Hund’s rule, to favor the filling of parallel spins.
Journal ArticleDOI
Quantum-confined Stark effect in single CdSe nanocrystallite quantum dots
TL;DR: In this paper, the quantum-confined Stark effect in single cadmium selenide (CdSe) nanocrystallite quantum dots was studied, and the electric field dependence of the single-dot spectrum is characterized by a highly polarizable excited state (∼10 5 cubic angstroms, compared to typical molecular values of order 10 to 100 cubic angramss), in the presence of randomly oriented local electric fields that change over time.