In this paper, a system of two or more quantum dots interacting with a dissipative plasmonic nanostructure is investigated in detail by using a cavity quantum electrodynamics approach with a model Hamiltonian. We focus on determining and understanding system configurations that generate multiple bipartite quantum entanglements between the occupation states of the quantum dots. These configurations include allowing for the quantum dots to be asymmetrically coupled to the plasmonic system. Analytical solution of a simplified limit for an arbitrary number of quantum dots and numerical simulations and optimization for the two and threedot cases are used to develop guidelines formore »


We have investigated a nanostructured material known as submonolayer typeII QDs, made from wide bandgap IIVI semiconductors. Our goal is to understand and exploit their tunable optical and electrical properties by taking advantage of the typeII band alignment and quantum confinement effects. TypeII ZnTe quantum dots (QDs) in a ZnSe host are particularly interesting because of their relatively large valence band and conduction band offsets. In the current award we have developed new materials based on submonolayer typeII QDs that may be advantageous for photovoltaic and spintronics applications. We have also expanded the structural characterization of these materials by refiningmore »

Organic–inorganic leadhalide perovskites have been the subject of recent intense interest due to their unusually strong photovoltaic performance. A new addition to the perovskite family is allinorganic Cs–Pbhalide perovskite nanocrystals, or quantum dots, fabricated via a moderatetemperature colloidal synthesis. While being only recently introduced to the research community, these nanomaterials have already shown promise for a range of applications from colorconverting phosphors and lightemitting diodes to lasers, and even roomtemperature singlephoton sources. Knowledge of the optical properties of perovskite quantum dots still remains vastly incomplete. Here we apply various timeresolved spectroscopic techniques to conduct a comprehensive study of spectral andmore »Cited by 38Full Text Available

Enhancementmode Si/SiGe electron quantum dots have been pursued extensively by many groups for their potential in quantum computing. Most of the reported dot designs utilize multiple metalgate layers and use Si/SiGe heterostructures with Ge concentration close to 30%. Here, we report the fabrication and lowtemperature characterization of quantum dots in the Si/Si_{0.8}Ge_{0.2} heterostructures using only one metalgate layer. We find that the threshold voltage of a channel narrower than 1 μm increases as the width decreases. The higher threshold can be attributed to the combination of quantum confinement and disorder. We also find that the lower Ge ratio used heremore »

Infrared (IR) light sources with high modulation rates are critical components for onchip optical communications. Leadbased colloidal quantum dots are promising nonepitaxial materials for use in IR lightemitting diodes, but their slow photoluminescence lifetime is a serious limitation. Here we demonstrate coupling of PbS quantum dots to colloidal plasmonic nanoantennas based on filmcoupled metal nanocubes, resulting in a dramatic 1300fold reduction in the emission lifetime from the microsecond to the nanosecond regime. This lifetime reduction is primarily due to a 1100fold increase in the radiative decay rate owing to the high quantum yield (65%) of the antenna. The short emissionmore »Cited by 1Full Text Available

In this study, luminescent solar concentrators (LSCs) can be utilized as both largearea collectors of solar radiation supplementing traditional photovoltaic cells as well as semitransparent “solar windows” that provide a desired degree of shading and simultaneously serve as powergeneration units. An important characteristic of an LSC is a concentration factor (C) that can be thought of as a coefficient of effective enlargement (or contraction) of the area of a solar cell when it is coupled to the LSC. Here we use analytical and numerical Monte Carlo modeling in addition to experimental studies of quantumdotbased LSCs to analyze the factors thatmore »Cited by 6Full Text Available

We study the combination of zerodimensional (0D) colloidal CdSe/ZnS quantum dots with tin disulfide (SnS_{2}), a twodimensional (2D)layered metal dichalcogenide, results in 0D–2D hybrids with enhanced light absorption properties. These 0D–2D hybrids, when exposed to light, exhibit intrahybrid nonradiative energy transfer from photoexcited CdSe/ZnS quantum dots to SnS_{2}. Using single nanocrystal spectroscopy, we find that the rate for energy transfer in 0D–2D hybrids increases with added number of SnS_{2} layers, a positive manifestation toward the potential functionality of such 2Dbased hybrids in applications such as photovoltaics and photon sensing.Cited by 9Full Text Available

This final report describes the activities undertaken under grant "Optical TwoDimensional Spectroscopy of Disordered Semiconductor Quantum Wells and Quantum Dots". The goal of this program was to implement optical 2dimensional Fourier transform spectroscopy and apply it to electronic excitations, including excitons, in semiconductors. Specifically of interest are quantum wells that exhibit disorder due to well width fluctuations and quantum dots. In both cases, 2D spectroscopy will provide information regarding coupling among excitonic localization sites.

Here, we consider a droplet of electrons confined within an external harmonic potential well of elliptical or ellipsoidal shape, a geometry commonly encountered in work with semiconductor quantum dots and other nanoscale or mesoscale structures. For droplet sizes exceeding the effective Bohr radius, the dominant contribution to average system parameters in the Thomas– Fermi approximation comes from the potential energy terms, which allows us to derive expressions describing the electron droplet’s shape and dimensions, its density, total and capacitive energy, and chemical potential. Our analytical results are in very good agreement with experimental data and numerical calculations, and make itmore »

In carrier multiplication, the absorption of a single photon results in two or more electron–hole pairs. Quantum dots are promising materials for implementing carrier multiplication principles in reallife technologies. So far, however, most of research in this area has focused on optical studies of solution samples with yet to be proven relevance to practical devices. We report ultrafast electrooptical studies of devicegrade films of electronically coupled quantum dots that allow us to observe multiplication directly in the photocurrent. Our studies help rationalize previous results from both optical spectroscopy and steadystate photocurrent measurements and also provide new insights into effects ofmore »Cited by 8Full Text Available
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