Search results for "quantum dot"
showing 10 items of 418 documents
Role of TiO2 in Highly Efficient Solar Cells
2021
Titanium dioxide (TiO2) is a naturally occurring oxide of titanium. It has a wide range of applications. It has three metastable phases, which can be synthesized easily by chemical routes. Usage of TiO2 in thin-film solar cells has gained much attention in increasing the performance of the cell. The objectives are to harvest the freely available earth’s energy and to gain expertise in yielding a maximum conversion efficiency. Various strategies are employed to face the challenges in improving the efficiency of solar cells. This study provides a broad view of the usage of different forms of TiO2 layers, like nanochannel, porous, nanotubes, and mesoporous layers, in enhancing electron injecti…
Propagation length enhancement of surface plasmon polaritons in gold nano-/micro-waveguides by the interference with photonic modes in the surroundin…
2017
Abstract In this work, the unique optical properties of surface plasmon polaritons (SPPs), i.e. subwavelength confinement or strong electric field concentration, are exploited to demonstrate the propagation of light signal at 600 nm along distances in the range from 17 to 150 μm for Au nanostripes 500 nm down to 100 nm wide (30 nm of height), respectively, both theoretically and experimentally. A low power laser is coupled into an optical fiber tip that is used to locally excite the photoluminescence of colloidal quantum dots (QDs) dispersed in their surroundings. Emitted light from these QDs is generating the SPPs that propagate along the metal waveguides. Then, the above-referred propagat…
Nanographenes: Ultrastable, Switchable, and Bright Probes for Super-Resolution Microscopy.
2019
Abstract Super‐resolution fluorescence microscopy has enabled important breakthroughs in biology and materials science. Implementations such as single‐molecule localization microscopy (SMLM) and minimal emission fluxes (MINFLUX) microscopy in the localization mode exploit fluorophores that blink, i.e., switch on and off, stochastically. Here, we introduce nanographenes, namely large polycyclic aromatic hydrocarbons that can also be regarded as atomically precise graphene quantum dots, as a new class of fluorophores for super‐resolution fluorescence microscopy. Nanographenes exhibit outstanding photophysical properties: intrinsic blinking even in air, excellent fluorescence recovery, and sta…
Temperature dependence of recombination radiation in semiconductor nanostructures with quantum dots containing impurity complexes
2021
Temperature dependence of the spectral intensity of recombination radiation in a quasi-zero-dimensional structure, containing impurity complexes “A++e” (a hole localized on a neutral acceptor, interacting with an electron localized in the ground state of a quantum dot), has been investigated in an external electric field in the presence of tunneling decay of a quasistationary A+-state. Probability of dissipative tunneling of a hole has been calculated in the one-instanton approximation, and the influence of tunneling decay and of an external electric field on the A+-state binding energy and on the spectra of recombination radiation, associated with the optical transition of an electron from…
Skin-derived mesenchymal stem cells as quantum dot vehicles to tumors
2017
Dominyka Dapkute,1,2 Simona Steponkiene,1 Danute Bulotiene,1 Liga Saulite,3 Una Riekstina,3 Ricardas Rotomskis1,4 1Biomedical Physics Laboratory, National Cancer Institute, Vilnius, Lithuania; 2Institute of Biosciences, Vilnius University, Vilnius, Lithuania; 3Faculty of Medicine, University of Latvia, Riga, Latvia; 4Biophotonics Group of Laser Research Center, Faculty of Physics, Vilnius University, Vilnius, Lithuania Purpose: Cell-mediated delivery of nanoparticles is emerging as a new method of cancer diagnostics and treatment. Due to their inherent regenerative properties, adult mesenchymal stem cells (MSCs) are naturally attracted to wounds and sites of inflammation, as well as tumors.…
Extending Quantum Links: Modules for Fiber‐ and Memory‐Based Quantum Repeaters
2020
We analyze elementary building blocks for quantum repeaters based on fiber channels and memory stations. Implementations are considered for three different physical platforms, for which suitable components are available: quantum dots, trapped atoms and ions, and color centers in diamond. We evaluate and compare the performances of basic quantum repeater links for these platforms both for present-day, state-of-the-art experimental parameters as well as for parameters that could in principle be reached in the future. The ultimate goal is to experimentally explore regimes at intermediate distances, up to a few 100 km, in which the repeater-assisted secret key transmission rates exceed the maxi…
Nanotexturing To Enhance Photoluminescent Response of Atomically Thin Indium Selenide with Highly Tunable Band Gap.
2016
Brotons-Gisbert, Mauro et al.
Synergy between quantum dots and 1,10-phenanthroline–copper(ii) complex towards cleaving DNA
2011
We have found that the DNA cleaving activity of quantum dots and 1,10-phenanthroline-Cu(II) complex is significantly enhanced when they are combined.
Two Novel Ternary Dicopper(II) μ-Guanazole Complexes with Aromatic Amines Strongly Activated by Quantum Dots for DNA Cleavage
2013
Two novel (μ-guanazole)-bridged binuclear copper(II) complexes with 1,10-phenanthroline (phen) or 2,2'-bipyridine (bipy), [Cu2(μ-N2,N4-Hdatrz)(phen)2(H2O)(NO3)4] (1) and [Cu2(μ-N1,N2-datrz)2(μ-OH2)(bipy)2](ClO4)2 (2) (Hdatrz = 3,5-diamino-1,2,4-triazole = guanazole), have been prepared and characterized by X-ray diffraction, spectroscopy, and susceptibility measurements. Compounds 1 and 2 differ in the aromatic amine, which acts as a coligand, and in the Cu···Cu'-bridging system. Compound 1, which contains two mono-bridged copper ions, represents the first example of a discrete Cu-(NCN-trz)-Cu' complex. Compound 2, with two triply bridged copper ions, is one of the few compounds featuring a…
Single quantum dot emission at telecom wavelengths from metamorphic InAs/InGaAs nanostructures grown on GaAs substrates
2011
3 figuras, 3 páginas.